This week in space: the red planet and the pale blue dot

Hello, readers, and welcome back to this last week in space in 2022. As the year draws to a close, American space — both public and private — has gone as quiet as a winter’s night. So, we console ourselves with triple Mars news. Climate scientists used Nvidia’s RTX ray tracing to create a completely new version of the blue marble. SpaceX also launched the first of its Gen2 Starlink satellites on Thursday. The cherry on top? We’ll wrap up with a few words about tonight’s once-in-a-lifetime skywatching opportunity.

NASA explores a winter wonderland — on Mars

Mars is a cold and forbidding place, with only a breath of carbon dioxide for an atmosphere. It’s winter in the northern hemisphere of Mars, just like here on Earth. And here, like Earth, Martian winters have a strange, harsh beauty. In celebration, NASA has released a collection of weird and wonderful images of winter snowscapes on Mars

It’s winter the cold Mars. So cold, in fact, that most of the Red Planet’s ‘snow’ is actually carbon dioxide that freezes out of the air into sandy, cube-shaped crystals of dry ice. Atmospheric pressure is so low that snow from water ice rarely reaches much of the Martian surface. Instead, it vaporizes before it hits the ground. NASA explains, “Snow falls only on the coldest parts of Mars: at the poles, behind clouds, and at night.”

Based on how water molecules form bonds when they freeze into ice crystals, terrestrial ice has six facets. The same principle applies to all crystals: the way the constituent atoms arrange themselves determines the shape of a crystal. In the case of carbon dioxide, dry ice molecules always form four bonds when frozen.

“Because carbon dioxide ice has four symmetries, we know dry-ice snowflakes will be cube-shaped,” said Sylvain Picoux, a member of NASA’s Mars Reconnaissance Orbiter team. “Thank you [MRO’s] Mars Climate Sounder, we can tell these snowflakes will be smaller than the width of a human hair.”

No Tannenbaum

The triangular spots on these snow-capped mountains are not Martian pines. These are just a few of the intricate patterns created when sunlight finally hits the snowy surface.

What we see are spots where gases escape from under the blanket of snow. As a puff of gas rises to the surface, it brings with it a fine sediment, which descends in a plume downwind. Scientists have learned to study these plumes to learn more about the prevailing winds on Mars.

minor fracture

The same phenomenon may have produced other exotic patterns elsewhere on the Martian surface. Transparent carbon dioxide ice allows sunlight to pass through and warm the dark sand below. It evaporates gases trapped in the soil.

NASA’s HiRISE orbiter captured this image near Mars’ north pole. Here, frozen water ice has broken the ground — and a layer of transparent CO2 ice above — into polygons. Repeated freeze-thaw cycles deepened the scattered cracks. This image has a finer spatial resolution than the others, only 25 cm (9.8 in) per pixel.

Fresh from the icebox

See “Holiday Ribbon Candy” (or the worst layer cake), these layers of dusty water ice deposits at the north pole of Mars are several miles thick. We can see the layer because of a trough that cuts through the deposit, exposing individual layers.

This HiRISE image of carbon dioxide avalanches developed on the poleward-facing slope inside a Martian crater. Because it receives less sunlight, it is cooler, so this is where ice condenses and freezes.

For links to these full-resolution images and more, see JPL’s feature and the MRO team’s slideshow.

NASA has confirmed that Martian dust will not bury the persistence rover’s sample tubes

Last week, InSight sent home its very last image before shutting itself down for good. Ultra-fine Martian dust has struck a lethal blow, covering solar panels and starving the lander of power. There’s something heartbreaking about the idea of ​​everything slowly turning dark for the tenacious little Lander. Perhaps in response to the eventual shutdown, NASA has reached out to reassure the public that the ever-present dust poses little threat to the sample tubes its diligent rover is cashing on Mars.

Air on Mars is constant, but because the atmosphere is so thin, the air does not carry much material. Thus, sample tubes should not be in any danger from drifting sand or dust.

After Artemis 1 overshot a critical launch window, NASA and ESA had to make some tough decisions about the future of those sample tubes. However, they learned a lot from the runaway success of Ingenuity, the tiny space copter that could. The two companies recently announced that they have scrapped plans to jointly collect samples on a large, tanky rover in favor of two space helicopters. from cleverness It turns out that opting out of surface obstacles is super-convenient when exploring another planet. This modification also avoids the problem of finding a heavy lift vehicle with a body wide enough to accommodate a bus-sized rover.

SpaceX launches first Gen2 Starlink satellite

SpaceX launched the first raft of Gen2 Starlink satellites from Canaveral on Wednesday evening. The new generation is bigger and more capable than their first generation counterparts. However, the Gen2 satellites are also distinguished by their orbital shells, although the first batch of satellites appear to be of an older design.

Watch Falcon 9 launch 54 Starlink satellites into orbit → https://t.co/wGq3KkoDyY https://t.co/sHdWRcsqZV

— SpaceX (@SpaceX) December 28, 2022

SpaceX says the Gen2 expansion will ease network congestion that the company has been battling all year. Meanwhile, one last Falcon 9 launch remains for the year.

Scientists have recreated the ‘blue marble’ with powerful new ray-tracing climate models

It was the 50th anniversary of Apollo 17. Although it was the last crewed mission to send us to the Moon in 50 years, the mission also produced the iconic ‘Blue Marble’ image of Earth. Now, in service of our dream of seeing and understanding the world as a whole, climatologists at the Max Planck Institute for Meteorology have created a fascinating new image that takes the blue marble to a whole new level.

The image above was created with the Nvidia Omniverse platform using internal RTX ray tracing. But this is no ordinary picture. The simulation is a fully formed world, with details that the Apollo crew’s cameras simply couldn’t capture. This fine-scale modeling allowed the team to look below the ocean’s surface, study waves of warm water emanating off the coast of Africa, and track cooler subsurface edges warmed by the sun.

Carl Sagan will so happy to see it

Skywatchers Corner Special Edition: Planets Align

This evening, Skywatchers are in for a once-in-a-lifetime show Just after sunset, all the planets in the solar system (even the moon!) will be visible in the sky at the same time, stretching out in a great cosmic arc across the southern sky.

Venus and Mercury are in conjunction, less than two degrees apart. Shortly after sunset, they will be visible low in the southwestern sky. Binoculars can help get a clear view of Mercury, as it is located in a bright part of the sky, orbiting very close to the Sun. On New Year’s Day, transitory Mercury will fade in solar light. Meanwhile, Jupiter will graze the edge of the waxing moon with about the same two-degree separation.

Assuming clear skies, you’ll be able to see Uranus and Neptune through binoculars or a telescope—a rarity in itself. Neptune takes 165 years to orbit the Sun, but Uranus takes 84 years. As a result, the two planets spend a lot of time on opposite sides of the sky. This planetary conjunction would not occur for longer than the time it took for the rise and fall of the Inca Empire. To find Neptune in the sky, look between Jupiter and Saturn; To find Uranus, look between Jupiter and Mars.

By the way: If you didn’t already know about it, this criminally underrated widget on NASA’s Skywatching page shows the most accurate information we have about the real-time positions of dozens of objects like Lucy, Vesta, OSIRIS-Rex, etc. Halley’s Comet, and 16 Psyche.

When you click on it, here’s what you’ll see:

From there, the tracker is clickable and zoomable, and contains all sorts of useful information about the tracked satellites and celestial objects. Enjoy it, and we’ll see you in the new year.

Read now:

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• NASA Cancels Geocarb Emissions Monitoring Mission