Space: The Final Frontier

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The Soyuz MS-12 launch that will bring three astronauts for the Expedition 59 to the ISS will take place today at 8 PM ECT and will be broadcast live on NASA TV.

 

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T-13 minutes until launch...

Love all the little rituals that they've been doing for years before every launch; like still playing that Трава у дома song, planting trees, etc. We might one day conquer space but we'll never stop being human  

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Expedition 59 has arrived and docked to the ISS successfully! 

 

[CaaC (John)+]

 

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US detects huge meteor explosion

A huge fireball exploded in the Earth's atmosphere in December, according to Nasa.

The blast was the second largest of its kind in 30 years, and the biggest since the fireball over Chelyabinsk in Russia six years ago.

But it went largely unnoticed until now because it blew up over the Bering Sea, off Russia's Kamchatka Peninsula.

The space rock exploded with 10 times the energy released by the Hiroshima atomic bomb.

Lindley Johnson, planetary defence officer at Nasa, told BBC News a fireball this big is only expected about two or three times every 100 years.

At about noon local time on 18 December, the asteroid barrelled through the atmosphere at a speed of 32km/s, on a steep trajectory of seven degrees.

Measuring several metres in size, the space rock exploded 25.6km above the Earth's surface, with an impact energy of 173 kilotonnes.

"That was 40% the energy release of Chelyabinsk, but it was over the Bering Sea so it didn't have the same type of effect or show up in the news," said Kelly Fast, near-Earth objects observations programme manager at Nasa.

"That's another thing we have in our defence, there's plenty of water on the planet."

Dr Fast was discussing the event here at the 50th Lunar and Planetary Science Conference in The Woodlands, near Houston, Texas.

Tough task

Military satellites picked up the blast last year; Nasa was notified of the event by the US Air Force.

Dr Johnson said the fireball came in over an area not too far from routes used by commercial planes flying between North America and Asia. So researchers have been checking with airlines to see if there were any reported sightings of the event.

In 2005, Congress tasked Nasa with finding 90% of near-Earth asteroids of 140 metres in size or larger by 2020. Space rocks of this size are so-called "problems without passports", because they are expected to affect whole regions if they collide with Earth. But scientists estimate it will take them another 30 years to fulfil this congressional directive.

Once an incoming object is identified, Nasa has had some notable success at calculating where on Earth the impact will occur, based on a precise determination of its orbit.

In June 2018, the small 3m asteroid 2018 LA was discovered by a ground-based observatory in Arizona eight hours before impact. The Center for Near-Earth Object Studies at Nasa's Jet Propulsion Laboratory (JPL) then made a precision determination of its orbit, which was used to calculate a probable impact location. This showed the rock was likely to hit southern Africa.

Just as the calculation suggested, a fireball was recorded over Botswana by a security camera footage on a farm. Fragments of the object were later found in the area.

Improved monitoring

But the latest event over the Bering Sea shows that larger objects can collide with us without warning, underlining the need for enhanced monitoring.

A more robust network would be dependent not only on ground telescopes, but space-based observatories also.

A mission concept in development would see a telescope called NeoCam launched to a gravitational balance point in space, where it would discover and characterise potentially hazardous asteroids larger than 140m.

Dr Amy Mainzer, chief scientist on NeoCam at JPL, said: "The idea is really to get as close as possible to reaching that 90% goal of finding the 140m and larger near-Earth asteroids given to Nasa by Congress.

She said that if the mission did not launch, projections suggested it would "take us many decades to get there with the existing suite of ground-based surveys".

Dr Mainzer added: "But if you have an IR-based (infrared) telescope, it goes a lot faster".

https://www.bbc.co.uk/news/science-environment-47607696

 

 

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[CaaC (John)+]

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Hayabusa-2: Asteroid mission exploring a 'rubble pile'

The asteroid being explored by the Japanese mission Hayabusa-2 is a "rubble pile" formed when rocks were blasted off a bigger asteroid and came back together again.

The discovery means that asteroid Ryugu has a parent body out there somewhere, and scientists already have two candidates.

They have also found a chemical signature across the asteroid that can indicate the presence of water, but this needs confirmation.

Ryugu's unusual shape is also a sign that it must have been spinning much faster in the past.

Scientists from the Japanese Space Agency (Jaxa) mission and from Nasa's Osiris-Rex spacecraft, which is exploring a different asteroid called Bennu, have been presenting their latest findings at the 50th Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas.

The Hayabusa-2 team has also published its results over three papers in Science journal.

Meanwhile, the team behind the Osiris-Rex mission has made the first close-up observations of particle plumes erupting from an asteroid's surface. These findings are published in a suite of papers in the Nature journals.

What have they learnt?

Bennu and Ryugu have many similarities. They are comparable in size, rich in carbon and shaped like spinning tops. Both missions aim to deliver samples from these objects to Earth.

Both asteroids are primitive objects, made of the same basic material that went into building rocky planets like Earth. Studying samples in laboratories could shed light on how our own world came to be.

The identification of Ryugu as a rubble pile asteroid comes from an assessment of its density. Project scientist Sei-ichiro Watanabe said the asteroid's porosity - a measure of the voids, or spaces, present in the object - was 50%.

The large number of rough boulders on Ryugu's surface support this idea, he added. These boulders are probably fragments that joined up after the disruption of its parent body.

What's the significance of shape?

The spinning top shape, Dr Watanabe said, "was formed from a past rapid rotation".

He added: "Most of the known top shapes are rapid rotators, but Ryugu is rather slow."

In fact, the scientists think that Ryugu once spun at twice its current rotation period of once every 7.6 hours. At some point in its history, the object slowed down, though what happened to cause this remains unclear.

Team-member Seiji Sugita, from the University of Tokyo, said: "The size of Ryugu is very small - 800m or 900m across. It's too small to survive the entire Solar System evolution of 4.6 billion years. Ryugu must have been born from a much older and larger parent body in relatively recent times - several hundred million years."

Analysis of the reflected sunlight from Ryugu shows it is a close match to two larger asteroids, known as Polana and Eulalia. These are good potential candidates for the asteroid's parent body.

What have they discovered about water?

Ryugu is surprisingly dark, much darker than any carbonaceous chondrite meteorites, which could partly be due to exposure of the rocks to the space environment.

"The surface of Ryugu is extremely dark," said Ralph Milliken, from Brown University in Rhode Island and a co-investigator on the near-infrared spectrometer instrument (NIRS3).

He held up a 3D-printed model of Ryugu, saying that he suspected the jet-black plastic used to make it was brighter than the real thing.

Data from NIRS3 has also revealed the presence of minerals with hydroxyl groups (OH), which can indicate the presence of water.

"There is evidence for water on Ryugu, but we do not have any strong evidence yet for the presence of molecular water, H2O," said Ralph Milliken.

The particular hydroxyl groups found on Ryugu appear to be associated with the element magnesium, which is often associated with clay minerals in meteorites.

What are the next steps in sample collection?

At Bennu, the team behind Osiris-Rex detected plumes of material erupting from the asteroid on 6 January this year. The immediate cause isn't clear, but it could be related to volatile gases that escape from the rocks when sunlight heats them up. This would push the dust out into space.

Bennu also appears to be a rubble pile asteroid, and, like Ryugu, was much more rugged than expected - posing a hazard for sample collection.

Hayabusa-2 has just finished a touchdown operation to collect a sample of rock and cache it for return to Earth.

Although there was no way to confirm if Hayabusa-2 had collected a sample, project manager Yuichi Tsuda said the team was confident it had, judging from the large amount of material kicked up after the spacecraft fired a 5g tantalum "bullet" into Ryugu's surface.

During the touchdown operation, Hayabusa-2's thrusters shifted 50cm-1m rocks, Yuichi Tsuda said. The thrusters also blew away the top layer of regolith, revealing darker material underneath.

Mission scientists have also set a date for Hayabusa-2's next set piece: the kinetic impact experiment. This will involve the spacecraft detonating an explosive charge near the surface of Ryugu - generating an artificial crater.

The spacecraft will move to the other side of Ryugu for safety when the charge goes off, returning later to grab a sample of rock from within the crater. The idea is for Hayabusa-2 to get at pristine samples from below the surface, samples that haven't been altered by aeons of exposure to space.

The operation will take place on 5 April, said Dr Tsuda.

https://www.bbc.co.uk/news/science-environment-47633649

 

 

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8 minutes ago, CaaC - John said:

Meanwhile, the team behind the Osiris-Rex mission has made the first close-up observations of particle plumes erupting from an asteroid's surface. These findings are published in a suite of papers in the Nature journals.

The image it took of those particle plumes is incredible...

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Today I read about a very interesting new fuel-free propulsion concept called "The Halo Drive", which could make it possible to accelerate a spacecraft up to a substantial percentage of lightspeed using gravity assist of binary black holes. 

 

[CaaC (John)+]

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NASA telescope spots a cosmic 'cannonball' hurtling through space

Jackson Ryan

NASA astronomers have discovered a pulsar zipping though space like a hyperspeed cosmic cannonball, travelling at 2.5 million miles per hour -- five times faster than your average pulsar.

At that speed, it's travelling at a startling 694 miles per second. If you could somehow build a cannon capable of firing this pulsar from the starboard side of your pirate ship in the Atlantic Ocean, it would speed around the Earth and hit your port side 35 seconds later. Arrrr!

Pirate ships aside, a pulsar is the rapidly rotating, dense star left behind in the wake of a massive supernova explosion. Astronomers believe that the explosion can send the pulsar hurtling through space like a cannonball. This one, named PSR J0002+6216, was discovered using NASA's Fermi Gamma-ray Space Telescope, which originally launched to space in 2008, and a suite of Earth-based radio telescopes known as the Karl G. Jansky Very Large Array.

PSR J0002+6216 -- or "J0002" -- is not like most of those other, standard, boring, pulsars we've seen before. No, J0002, is like the Sonic the Hedgehog version of a pulsar -- faster than 99 percent of those we've measured in the past. Thanks to Fermi, which launched in 2008, there is a decade of data with which to analyze J0002, meaning the research team could provide an accurate measurement of its movements.

© CNET Jayanne English, University of Manitoba/NRAO/F. Schinzel et al., DRAO/Canadian Galactic Plane Survey and NASA/IRAS

"The longer the data set, the more powerful the pulsar timing technique is," said Matthew Kerr, a researcher with the US Naval Research Laboratory. "Fermi's lovely 10-year data set is essentially what made this measurement possible."

J0002 currently lies about 6,500 light-years away in a constellation known as Cassiopeia, and 53 light-years away from the remnants of a huge stellar explosion known as CTB 1. That explosion took place around 10,000 years ago and resulted in a rapidly expanding bubble of gas that engulfed the pulsar.

But around 5,000 years ago, the incredibly fast pulsar would have burst though the ghostly gas cloud, and continued speeding away, resulting in the fabulous image at the top of this article showing a streaky, fiery yellow tail. That tail looks small in the image, but it extends 13 light-years behind the speeding cosmic cannonball.

The tail also allows astronomers to trace the origin of the pulsar, giving them a better chance to understand how it formed and how it was ejected from the supernova explosion.

"Further study of this object will help us better understand how these explosions are able to 'kick' neutron stars to such high speed," said Frank Schinzel, a scientist at the National Radio Astronomy Observatory.

The pulsar was first discovered in 2017 as part of a citizen-science project known as Einstein@Home. That project uses the processing power of idling computers to search Fermi's mountain of data for hints of a pulsar and, to date, has enabled the discovery of 23.

https://www.msn.com/en-gb/news/techandscience/nasa-telescope-spots-a-cosmic-cannonball-hurtling-through-space/ar-BBV1XlP?ocid=chromentp

 

 

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Latest update: The spacecraft has entered the lunar orbit!

 

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The more the merrier I say, "Beam me up, Scotty"  

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3 minutes ago, CaaC - John said:

The more the merrier I say, "Beam me up, Scotty"  

Absolutely! I'm enjoying this latest "moon race" as it has a great potential to speed up the progress of further space exploration.

India is set to launch Chandrayaan-2 (a lander and a rover) in April; they missed the launch window in January.

 

Germany-based private group of rocket scientists and engineers are aiming to land two Audi-branded robotic rovers on the moon by the end of the year )beginning of 2020 looks more likely) and it will be the first mission ever to revisit the original Apollo landing site.

 

Japan is going to launch a tiny impactor in December followed by a smart lander early next year.

 

At least a few other countries are launching orbiters this year as well (Brazil; South Korea).

And then of course we have Chang'e 5, the next step in China's moon mission that will bring the lunar samples back to Earth!

[CaaC (John)+]

 

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Planet Venus: Hopes rise of new mission to the hothouse world

The longstanding idea that Venus is geologically dead is a "myth", scientists say.

And new research may be on the verge of ending that perception forever.

Hints of ongoing volcanic and tectonic activity (activity in the planet's outer shell) suggest that, while different to the Earth, the planet is very much alive.

Now scientists are building new narratives to explain the planet's landscape.

This includes an idea that proposes the existence of "toffee planets". This theory incorporates knowledge accumulated through studying exoplanets.

The new ideas have been discussed here at the 50th Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas.

Historic missions

The focus on Mars over the last few decades has transformed our view of that planet's geology.

In the meantime, the researchers who study Venus's surface have relied heavily on data from Magellan - a Nasa mission that ended in 1994. A European mission, Venus Express, and a Japanese spacecraft, Akatsuki, have been there since, but both are focused on atmospheric science.

After years of feeling like a new mission would never happen, there is a sense that the tide might finally be turning.

The European Space Agency (Esa) is evaluating a Venus mission, called EnVision, alongside two astronomy proposals - Theseus and Spica. Other concepts are also being proposed to Nasa.

Early career researchers are now choosing to join the field again in numbers. And scientists with backgrounds in other disciplines are lending their expertise, bringing new ideas.

Venus is a hothouse world, with a surface temperature of 500C - hot enough to melt lead. But it's not just the heat that makes it inhospitable: the planet's thick atmosphere has cranked the surface pressure up to 90 bars. That's the equivalent to what you'd experience 900m below the sea.

But Venus and Earth started out being much more similar. "They probably started out as twins, but they've diverged," said Dr Richard Ghail, from Royal Holloway, University of London, who is the principal investigator on EnVision.

"The Earth in that time has gained oxygen and life and has - essentially - quite a cold climate, whereas Venus has got incessantly hotter and drier over a long period."

Lost water

Like Mars, then, Venus might even have had the right conditions in the past for life. But Dr Ghail says that while the Red Planet could have hosted large bodies of water on its surface for about 100 million years, Venus could have harboured oceans for more than a billion years of its early history.

How and when it lost that water is just one of the puzzles scientists want new missions to shed light on. Its fate might even present an extreme future pathway for the Earth.

The history of Venus exploration with robotic probes goes back more than 50 years. If the US has become synonymous with Mars exploration, it was the Soviets who stamped their mark on our nearest neighbour in the 1960s, 70s and 80s.

They launched nearly 30 probes towards the planet, with several notable failures. But the successful missions sent back crucial data, including images of the surface. One probe made a detection of what could have been lightning, while others analysed rock samples, which were found to be basalts - similar to general types found on Earth.

Part of the resurgence of interest in Venus centres around the type of geological activity going on, and what it may tell us about rocky planets in general.

Tectonic activity

Venus is thought to lack plate tectonics, the process responsible for recycling the Earth's crust. But the notion that Venus has essentially been "dead" since an outpouring of volcanism hundreds of millions of years ago is incorrect in the view of a growing number of researchers.

Many signs of tectonic activity on Earth, such as networks of ridges and faults, can be found on Venus.

Dr Ghail has identified signs that Venus's crust is broken up into blocks measuring on the order of 500-1,000km across, which move around slowly in much the same way that pack ice floats on an ocean, pushing and rubbing against each other. The process is driven by convection (the process of heat transfer which pushes hotter material upwards and cooler, denser material down) in the mantle region below the crust.

"They are moving into the block next to them, and that's moving the block next to it and so on. You can link those things together and see that everything is moving towards Ishtar in the northern hemisphere," the Royal Holloway researcher told BBC News.

Ishtar Terra is one of the main highland regions of Venus, sometimes described as a "continent".

"I think you take enough pack ice, you squeeze it into one place, thicken it up and you make a big high plateau," Dr Ghail explained.

Toffee planet

Dr Paul K Byrne, from North Carolina State University, says this idea might fit in well with a theory he has been developing about the relationship between the thickness of the lithosphere, the rigid outer shell of a planet, and its gravity.

"The basic thinking is this: because on a world with lower gravity, you might get a thicker layer, we reasoned that if you've got higher gravity - like a Super-Earth (a class of medium-sized planet seen around other stars but not in the Solar System) - then that brittle layer would be proportionally thinner."

He calculates that particular combinations of planetary mass, atmospheric pressure and composition, as well as the distance of a planet to its star, can produce something called a toffee planet, where the lithosphere is very thin.

"For example, one of the ways that lava might come up is that magma will rise to some depth and make its way through fractures or dykes. But if you don't have a thick layer… then it won't come up in that nice easy way. It might come up in a larger mass, but it won't be concentrated so you won't expect to find chains of volcanoes," Dr Byrne explained.

With regards to Venus, he said: "Some parts of Venus we think might be quite thick, but some parts of Venus, in the lowlands, the brittle layer might be quite thin."

Under that scenario, the idea of blocks of crust moving like pack-ice becomes plausible, said Dr Byrne. If selected, EnVision will carry a synthetic aperture radar to test some of these ideas.

"I think this is happening, other people think nothing's happening. The other possibility is that it's really Earth-like and really active… the only way to distinguish between those is with radar. We do that routinely on Earth, so let's take an Earth-observation radar to Venus," said Dr Ghail.

https://www.bbc.co.uk/news/science-environment-47672736

 

 

 

Edited March 23, 2019 by CaaC - John

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17 minutes ago, CaaC - John said:

The European Space Agency (Esa) is evaluating a Venus mission, called EnVision, alongside two astronomy proposals - Theseus and Spica. Other concepts are also being proposed to Nasa.

It's a bit underwhelming that all proposals only consider yet another orbiter... It would be really exciting to finally get a lander again; preferably one that could survive Venus' deadly surface for longer than just hours. I understand that the incredibly harsh environment brings a lot of challenges and I also realise that budget limitation play a big role here but it's still somewhat disappointing...

[CaaC (John)+]

18 minutes ago, nudge said:

preferably one that could survive Venus' deadly surface for longer than just hours.

I can't see a landing surviving though with the temp at 500c, maybe in many more years when you and me are not here on earth anymore and Venus will cool down a lot by then, it's strange really as we (mankind) is reaching out in space but we still can't go to the deepest ocean on this world, Challenger Deep, a section of the Mariana Trench under the Pacific Ocean because we would be crushed.

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2 hours ago, CaaC - John said:

I can't see a landing surviving though with the temp at 500c, maybe in many more years when you and me are not here on earth anymore and Venus will cool down a lot by then, it's strange really as we (mankind) is reaching out in space but we still can't go to the deepest ocean on this world, Challenger Deep, a section of the Mariana Trench under the Pacific Ocean because we would be crushed.

The Soviets landed numerous probes in Venus that not only survived the landing but also transmitted data and even took photos for over 2 hours in the 60s and 70s. It's challenging, but it's definitely feasible. With the advancement of technology (we already have the technology needed for heat and pressure resistant electronics and materials), there have been quite a few concepts for a Venus lander (including both "simple" probes as well as rovers) that have been proposed; at least two of them were even proposed as potential targets for the next upcoming New Frontiers mission, but were unfortunately not chosen... That's why I'm a bit frustrated with another orbiter (for the mission in over 10 years, nonetheless!) while we do have the means but are seemingly not willing to push ourselves further.

What do you mean by saying that we can't go to Challenger Deep? We've been there before twice and are about to go there again with the Five Deeps Expedition! It's baffling considering how little media coverage that mission gets. The team already managed to go down to two of the five deepest points (in Atlantic and Southern oceans), are currently preparing to do the next one in the Indian ocean, the descent to the Challenger Deep is planned for May 19th and they will then finish the mission by going down to the deepest spot in the Arctic ocean in September. Can't wait until all that is made into a documentary.

So in both cases (Venus landing and deepest ocean trenches), I'd say it’s not the technology which hampers the scientists, it’s the funding.

[CaaC (John)+]

3 hours ago, nudge said:

What do you mean by saying that we can't go to Challenger Deep? We've been there before twice and are about to go there again with the Five Deeps Expedition!

I forgot about that, I would love to go deep sea diving but at my age now and health wise (asthma, sciatica etc) that's an impossibility...sigh  

[CaaC (John)+]

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On Pluto, It’s Been Spring Since 1990

Marina Koren

Ah, spring.

The season of vibrant flowers lining the sidewalk on the commute home, their gentle fragrance wafting into the air. Of sunshine that calls for a light jacket instead of a bulky coat. Of the passionate urge to clean everything in sight.

Outside The Atlantic’s Washington, D.C., headquarters, it’s about 43 degrees Fahrenheit (6 degrees Celsius)—not warm enough for open-toed shoes, but still more pleasant than, say, a polar vortex. I’ve been longing for this day, and it got me thinking about spring on other planets, and whether it even exists.

We owe the seasons to Earth’s axis, which stays tilted at about 23 degrees as the Earth loops around the sun. But the orientation of the planet’s hemispheres in relation to the sun changes; different parts of the Earth lean toward or away from the sun at different times of the year, and receive varying amounts of sunlight.

But how do other planets work? To find out, and also to procrastinate my spring cleaning, I reached out to some scientists who spend their days thinking about other worlds.

Mercury

“Mercury doesn’t really have anything approaching spring, or any season for that matter,” says Paul Byrne, a planetary geologist at North Carolina State University. The planet’s axial tilt, a fraction of a degree, is negligible. “The amount of daylight at a given latitude on Mercury is essentially fixed during the entire year.”

The daylight is relentless and scorching. But the orientation produces a rather cool phenomenon. “It lets Mercury have regions of permanent shadow near its poles that are never sunlit, and lets ice be present in those regions—even on the planet closest to the sun,” says Nancy Chabot, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory.

“It’s one weird little planet,” Byrne adds.

Venus

“There is no springtime on Venus, nor any other season—no seasons in hell!” says Allan Treiman, a scientist at the Lunar and Planetary Institute.

It’s difficult to sugarcoat the environment on Venus. Surface temperatures are a sizzling 870 degrees Fahrenheit (470 degrees Celsius), hot enough to melt lead, all year round. Like Mercury’s, Venus’s axis isn’t tilted enough to produce a noticeable difference.

But the real reason the planet doesn’t have any seasons is its atmosphere, which is choked with clouds. “The clouds are so thick that its surface gets nearly no light or heat from the sun. Nearly all the sunlight and heat are absorbed by clouds, which then radiate heat down to the surface—the famous greenhouse effect,” Tremain says. “Venus clouds circulate faster than the surface does, so all the greenhouse heat is spread around the planet, whether it’s day or night.”

That’s not all. “To top everything else off, Venus’ day is longer than her year,” says Vicki Hansen, a scientist at the Planetary Science Institute. (It takes 243 Earth days for Venus to rotate once on its axis, but 225 Earth days for the planet to loop around the sun.) “So if she had spring, it would be hard to say what day it happened.”

Mars

Mars’s axis is tilted slightly more than Earth’s—about 25 degrees—which means the planet experiences distinct seasons, too. In fact, like the Northern hemisphere here, the Northern hemisphere on Mars is entering spring now.

“The Northern hemisphere is starting to heat up; the Southern hemisphere cooling off—just like on Earth,” says Don Banfield, a scientist at the Cornell Center for Astrophysics and Planetary Science.

Well, not just like on Earth. Orbits affect seasons, too; the Martian year is twice as long as a terrestrial year, so the seasons stretch out longer. There are seasonal trends, such as summer dust storms, “but without rain and plants, they aren’t quite as obvious,” says Banfield.

Jupiter

“Jupiter does not have a springtime,” says Cheng Li, a scientist at NASA’s Jet Propulsion Laboratory. Like Mercury, Jupiter’s axial tilt is too small to matter.

Saturn

Saturn does have spring: Its axial tilt is similar to that of Earth and Mars.

“Saturn is warm in the summer and cold in the winter,” says Leigh Fletcher, a planetary scientist at the University of Leicester. “The clouds and chemicals respond to these changes in sunlight. Perhaps the best example is the color of Saturn’s atmosphere, which shifts from blue hues in the winter—relatively clear skies with very few hazes—to golden hues in summer—a more smoggy atmosphere with lots of hazes.”

Saturnian spring also provides the most visibility for a massive, hexagon-shaped storm at the planet’s north pole that has mesmerized scientists for years. Some parts of Saturn can even experience miniature versions of seasons, thanks to its shimmering rings.

“A fixed point in Saturn’s atmosphere would experience additional periods when the rings shade the sun,” says Mike Wong, a planetary scientist at the University of California, Berkeley. “We actually have something like this at my house, because the neighboring building has a billboard on top. From a certain date in November to a certain date in February, our roof is in constant shade because the billboard blocks the sun, so our house gets colder.”

Uranus

With a 98-degree tilt of its axis, Uranus basically spins on its side. This alignment means the planet experiences the most extreme seasonal contrasts in the solar system.

“The poles get a great deal of illumination from an overhead sun that barely seems to move in the sky during local summer and a great deal of darkness in winter,” says Glenn Orton, a scientist at NASA’s JPL. “As spring begins, the sun is virtually always at the horizon for anyone living at the poles and virtually straight overhead for a Uranian in the low-latitude tropics.” (We should clarify: These are fictional Uranian residents. Alien life hasn’t been discovered there.)

During spring, a giant white cap emerges over the north pole, standing out against the planet’s usual blue hues. Scientists suspect the warming temperatures produce atmospheric changes.

This far out in the solar system—where orbits are vastly longer—seasons stretch out for years. A Uranus spring lasts 21.

Neptune

Spring on Neptune is twice as long. The planet experiences distinct seasons, but “I don’t think we’ve been able to observe Neptune long enough with enough detail to say for sure how spring in one hemisphere differs from any other season in terms of atmospheric activity,” says Anne Verbiscer, a planetary scientist at the University of Virginia.

Pluto

“Why yes, it’s springtime on Pluto right now, at least in the northern hemisphere!” says David Grinspoon, a scientist at the Planetary Science Institute. “And it has been since 1990.”

(Please don’t overthink the inclusion of Pluto on this list. Scientists have spent years arguing over the correct categorization of this celestial body. For some of them, the 2006 decision to reclassify Pluto as a dwarf planet is not the final word. We’ll leave the debating to them.)

Pluto’s orbit around the sun is highly elliptical. “The distance to the sun is quite different for the same season in the south versus the north,” Grinspoon says. “This creates asymmetrical and extreme climate behavior where, over the timescale of the seasons—which are many decades long—the atmosphere goes through the magnitude of changes that on other planets we would call climate changes.”

Spring sounds mild compared with colder seasons. Without enough exposure to sunlight, Pluto can get so cold that its atmosphere freezes and falls on the surface. “You can imagine what life would be like if we had that experience on Earth,” says Bob West, a scientist at JPL. “The air we breathe and which sustains all life on the dry land would form crystals of water, oxygen, nitrogen, and carbon dioxide and fall to the ground as snow, leaving a near vacuum where once there was air.”

Wow. A little spring cleaning doesn’t sound so bad now.

https://www.msn.com/en-gb/news/spotlight/on-pluto-its-been-spring-since-1990/ar-BBV53QJ?li=BBoPWjQ&ocid=mailsignout

 

 

 

[CaaC (John)+]

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Exoplanet tally set to pass 4,000 mark

The number of planets detected around other stars - or exoplanets - is set to hit the 4,000 mark.

The huge haul is a sign of the explosion of findings from searches with telescopes on the ground and in space over the last 25 years.

It's also an indication of just how common planets are - with most stars in the Milky Way hosting at least one world in orbit around them.

That's something astronomers couldn't be certain of just 30 years ago.

The Extrasolar Planets Encyclopedia, run by the Observatoire de Paris, has already passed the 4,000 mark.

Dr Françoise Roques, from the observatory, who is on the scientific board of the encyclopedia, told BBC News: "The great news is that we shift from a starry sky to a planetary sky, as there are more planets than stars.

"And also that the planetary systems have great diversity of structure, with planets orbiting zero, one, two... stars, or other planets."

The Nasa Exoplanet Archive is 74 planets away from the milestone. But there are 443 planet candidates detected by Nasa's Tess space telescope (launched in 2018) awaiting confirmation.

There are a further 2,423 candidates detected by the Kepler space telescope.

The latest exoplanet to be added to the Nasa archive was the Super Earth GI 686 b, which orbits a red dwarf star (a type cooler than our Sun) which was discovered using ground telescopes. It was added on 21 March.

The total number of confirmed planets differs between the two catalogues because of slightly different acceptance criteria - along with other factors.

The early technique of detecting new worlds by the "wobble" induced by a planet's gravitational tug on its star yielded many giant planets known as "hot Jupiters", which orbited close to their stars. These planet types were easier to detect using the wobble method.

Nasa's Kepler space telescope was launched in 2009; it used a different technique known as the transit method to measure the dip in brightness as a planet passed in front of its host star. Kepler discovered hundreds of Neptune-sized planets and those that fell into a category known as Super Earths (those having a mass larger than Earth's but below those of Neptune-sized planets).

Dr Roques said it remained a difficult task to distinguish between a type of star known as a brown dwarf and giant planets.

"Four-thousand is just a number as the frontier of the planet domain is uncertain," she said.

"The brown dwarfs have been defined by the [IAU - International Astronomical Union] as small stars, but in fact, some of them are big planets. Our database collects objects until 60 Jupiter masses and contains a mix of the planetary brown dwarfs (formed in a protoplanetary disk around a star) and starry brown dwarfs (formed by collapse of interstellar cloud).

"The only way to ensure the difference is to access its internal structure, which is a difficult/ impossible task."

The first exoplanets were found around a pulsar - a highly magnetised neutron star - in 1992 by Aleksander Wolszczan and Dale Frail.

The initial discovery of a planet around a main sequence star - those that fuse hydrogen into helium within their cores - was made in 1995 by astronomers Didier Queloz and Michel Mayor.

Dr Roque explained: "For the field of exoplanet exploration, we [are going] from discovery projects to exploration projects, for a better understanding of the structure, formation, atmosphere and, of course habitability of exoplanets."

https://www.bbc.co.uk/news/science-environment-47681239

 

 

[CaaC (John)+]

Quote

NASA’s ‘historic’ spacewalk no longer all-female due to spacesuit availability: officials

Ann Schmidt

© FoxNews.com Nick Hague and Anne McClain replace nickel-hydrogen batteries with newer, more powerful lithium-ion batteries on the ISS; Phil Keating reports from Miami, Florida.

Plans for NASA’s upcoming spacewalk have been altered.

The March 29 assignment was supposed to be the first all-female spacewalk, but there won't be enough of the correctly-sized spacesuits ready in time for Friday, so it will be performed by a man and a woman instead, a NASA press release said Monday.

Anne McClain and Christina Koch, two NASA astronauts with Expedition 59, had been scheduled to operate the spacewalk, but mission managers decided to switch so that Koch and NASA astronaut Nick Hague could operate the assignment.

Hague and McClain operated the first spacewalk out of a series of three on March 22.

© inhauscreative

They began installing lithium-ion batteries for a pair of solar arrays on the International Space Station, according to the release.

While McClain was on the assignment -- which was also her first spacewalk -- she found that the best-fitting “shirt” of the spacesuit was medium-sized.

However, there is only one medium-sized hard upper torso at the space station that will be ready in time for Friday’s spacewalk, so Koch will wear it, the release said.

It will be Koch’s first spacewalk. She and Hague will be completing the battery installation.

As of now, McClain will perform her second spacewalk on April 8, for the third of the series.

McClain will be accompanied by Canadian Space Agency astronaut David Saint-Jacques, though the assignments will be finalized after Friday’s spacewalk is finished.

Initially, Hague and Saint-Jacques were scheduled to perform the April 8 spacewalk together.

Spacewalks, also called extravehicular activity (EVA), usually last between five and eight hours and are conducted so that astronauts can make repairs on equipment or carry out experiments. Each of the upcoming spacewalks on March 29 and April 8 are expected to last about six and a half hours, according to the release.

https://www.msn.com/en-gb/news/techandscience/nasas-historic-spacewalk-no-longer-all-female-due-to-spacesuit-availability-officials/ar-BBVdWE0?ocid=chromentp

 

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Edited March 26, 2019 by CaaC - John

[nudge]

New study: The giant planet Jupiter was formed four times further from the sun than its current orbit, and migrated inwards in the solar system over a period of 700 000 years. Researchers found proof of this incredible journey thanks to a group of asteroids close to Jupiter.

https://www.lunduniversity.lu.se/article/jupiters-unknown-journey-revealed

An interesting read.

[CaaC (John)+]

Quote

NASA now aims to return astronauts to the moon within 5 years

Eric Mack

Astronaut Buzz Aldrin on the lunar surface. 

At a meeting of the National Space Council on Tuesday, Vice President Mike Pence challenged NASA to put astronauts back on the moon by 2024, moving up the agency's previous timeline for a return to the lunar surface.

"What we need now is urgency," Pence said during a speech to a crowd at the US Space & Rocket Center in Huntsville, Alabama. "It is the stated policy of this administration and the United States of America to return American astronauts to the moon within the next five years."

NASA administrator Jim Bridenstine, appointed by President Donald Trump, later accepted the challenge, calling it "right on time."

"NASA is going to do everything in its power to meet that deadline," Bridenstine said. 

Bridenstine's Twitter account also sent out a link to NASA's Moon to Mars page that still listed 2028 as the target for putting new boots on the lunar surface. The page has since been revised to show the new 2024 target for astronauts on the moon.

Pence's speech echoed overtones of the Cold War tensions that drove NASA to achieve the original Apollo 11 moon landing on schedule 50 years ago this July.  Pence said we're in the midst of another space race, citing China's recent landing on the far side of the moon and saying that it "revealed their ambition to seize the strategic lunar high ground."

He also mentioned the reliance on Russian rockets to send American astronauts to orbit over the past decade, something the agency hopes to bring to an end with new spacecraft designed by SpaceX, Boeing and NASA itself.

Astronauts Set An American Flag On The Moon. 3D Illustration.

"The first woman and the next man on the moon will both be American astronauts, launched by American rockets from American soil." 

Pence was also explicit that meeting the new five-year goal should be accomplished "by any means necessary," including switching to commercial rockets. NASA has planned to send astronauts beyond orbit using its new Space Launch System (SLS) and the Orion spacecraft, but SLS has been plagued by delays.

https://www.msn.com/en-gb/news/techandscience/nasa-now-aims-to-return-astronauts-to-the-moon-within-5-years/ar-BBVgYYC?li=AAnZ9Ug&ocid=mailsignout

 

 

[CaaC (John)+]

22 hours ago, nudge said:

New study: The giant planet Jupiter was formed four times further from the sun than its current orbit, and migrated inwards in the solar system over a period of 700 000 years. Researchers found proof of this incredible journey thanks to a group of asteroids close to Jupiter.

https://www.lunduniversity.lu.se/article/jupiters-unknown-journey-revealed

An interesting read.

Good read and I loved this bit, and the photo, it sent a shiver down my spine. 

"According to the calculations, Jupiter’s migration went on for around 700 000 years, in a period approximately 2-3 million years after the celestial body started its life as an ice asteroid far from the sun. The journey inwards in the solar system followed a spiralling course in which Jupiter continued to circle around the sun, albeit in an increasingly tight path. The reason behind the actual migration relates to gravitational forces from the surrounding gases in the solar system".