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May 7 2018

Guest Videos: Sentinel Spots Suspicious Movement of English Village

Not in the village, of the village.

Here’s the village–I don’t know why the bicyclists are driving cars, but that’s Willand in Devonshire they’re driving through:

And this is the Sentinel that has discovered Willand is rising at a rate of almost an inch a year

It’s a total mystery. This is not a tectonically active region, so things like volcanism or plate collisions are unlikely to be involved. The mining boom during the Industrial Age also passed Willand by.

According to this source, whatever is causing it is deep underground, perhaps an aquifer that is filling up.

Willand residents aren’t endangered by the movement, but it will affect major transportation corridors that are planned for the area.

Apr 30 2018

Guest Videos: Space Telescopes

You might be able to view this unusual video. I can’t, but it is getting all the good reviews.

They posted “Fistful of Stars” as a regular video, though it’s designed for virtual reality. Check it out, if you can.

That’s actually just art–part of the Hubble Cantata.

Hubble itself is old, in space terms, and new scopes are on the planning horizon.

The next big one will be the Webb Telescope. NASA recently pushed back its launch date to correct sunshield and cable problems found during a March 2018 test. It’s now expected to go up in 2020.

And, as mentioned in that video, the next “space” telescope after Webb will stay on Earth, in Chile’s Atacama Desert! The Giant Magellan Telescope is due for completion in 2025.

Bumping into new discoveries–I like that!

I think.

As Georges Méliès knew back in 1898, astronomers’ dreams sometimes go awry.

Featured image: NASA Hubble

Apr 26 2018

Guest Video: Sniffing Out Methane on Mars

On April 10, the European Space Agency announced that the trace gas orbiter–Part 1 of its ExoMars mission to the Red Planet–has finished aerobraking:

Here’s why they are so interested in Martian methane.

NASA also has a 2020 mission planned and is hoping to retrieve some rocks. (Uh, guys, you’ve already got some!)

Featured image: ESA/ATG medialab

Apr 25 2018

Guest Video: How to Turn a Meteorite Into a Sword

Then Beleg chose Anglachel; and that was a sword of great worth, and it was so named because it was made of iron that fell from heaven as a blazing star…

— J. R. R. Tolkien, in “The Silmarillion”

Until light sabers are developed, humanity must continue to do hard physical labor to get space swords.

(Here is the link given at the above video’s site for the carbonization thing.)

Apr 11 2018

Guest Video: Saharan Desert Glass

Once upon a time, a shallow tropical sea called Tethys separated Africa and Eurasia, covering what is now the Sahara Desert and connecting the Atlantic and Pacific oceans with an equatorial belt of warm water.

Then, one day almost 30 million years ago, something from space burned in through the atmosphere, either striking our planet near the Sahara’s location or exploding in the air above it.

This impact, while nothing like the event that caused a major mass extinction 65 million years ago, was more powerful than an atomic explosion–strong enough to turn exposed areas of quartz-rich sand into glass.

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James St. John, CC BY 2.0

Around 19 million years ago, the Arabian tectonic plate began to collide with Eurasia. Slowly, inexorably, land sealed off and isolated what had been the western arm of Tethys, turning it into the Mediterranean Sea.

For this and many other reasons, the world’s climate changed dramatically, and the Sahara became a desert.

Millions of years later, human beings who knew how to survive and prosper in this great desert came along and used this unusual material for tools and, later on, jewelry.

However, seen under a microscope, the Sahara still harbors jewel-like grains of sand.

Featured image: Western Desert sand grains. Wilson44691. Public domain.

Sources

Agustí, J., and Antón, M. 2002. Mammoths, Sabertooths, and Hominids: 65 Million Years of Mammalian Evolution in Europe. New York and Chichester: Columbia University Press.

Giuli, G., Paris, E., Pratesi, G., Koeberl, C., & Cipriani, C. (2003). Iron oxidation state in the Fe‐rich layer and silica matrix of Libyan desert glass: A high‐resolution XANES study. Meteoritics & Planetary Science, 38(8), 1181-1186.

Apr 5 2018

Follow the Water, Part 1: The Early Solar System

There have been some interesting news stories recently about ancient water here and on Mars. They are hard to describe in plain English, though–at least in a single post.

Spread out over two or three posts, with lots of videos, it’s easier to follow this water.

First, let’s start up the Solar System:

There is a lot of water in there, per NASA. It may have originated in interstellar space, becoming part of the solar nebula before that collapsed to form the Sun.

Any water that was present near the Sun disappeared when this star fired up. Back then, the neighborhood was hot enough to vaporize carbon, let alone boil away any oceans that tried to form. Indeed, as Mercury, Venus, Earth, and Mars took shape, they must have lost several elements through vaporization, including hydrogen.

And without H you can’t have H2O.

Obviously water got to Earth somehow. Scientists thought for a long time that it arrived via comets–basically, big dirty snowballs that reside in the outer reaches of the Solar System. Impact by impact, according to this hypothesis, our planet collected water after the new Sun had settled down a bit.

But when the European Space Agency intercepted a comet in 2014, they discovered that its water had a different isotope “signature” than ours.

This complicated things. Then, in 2017, scientists learned that a certain type of meteorite called angrite contains water (not sloshing around but locked inside the rock).

That’s the important thing you should take away from this post: there can be water inside rocks, as well as flowing around them (like groundwater) or over them (like a stream).

These water-containing angrite meteorites formed very soon after the Sun did, apparently far enough away from the brilliant new star to avoid getting cooked. Which brings us to the first really cool news recently.

A huge collision happened in our neighborhood, forming the Earth and the Moon:

This isn’t news, although the details are still being worked out. But get this–even at that early point, the part that became Earth may have already had at least 70% of its present water!

It’s hard to believe, but water can be locked up in rock, even when it’s molten after an impact.

So there’s no particular reason to expect that all of a planet’s water is on its surface. This points toward some other scientific headlines lately about water deep inside the Earth–and possibly even within the apparently bone-dry planet Mars.

To be continued

Featured image: Pacific Ocean, from the International Space Station, NASA via Wikimedia.

Mar 31 2018

Want the Latest on the Falling Chinese Space Station?

Update, 6:22 p.m.: The Pacific got any debris:

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Update, 5:42 p.m., Pacific:

Hopefully, the people of Chile and Argentina have caught a break – seeing a night-time spectacle, without any debris fall hitting nearby!

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Update, 5:37 p.m.:

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Update, 5:35 p.m.: It’s off Aerospace’s online tracking map; just checked that, so I don’t know when they took it off. It was over the Pacific, last time I checked the map.

Update, 5:32 p.m.: Per La Vanguardia, China’s Manned Space Flight center (CMSEO) says that Tiangong debris will arrive in the south central Atlantic at 00:49 UTC.

Update, 5:22 p.m. Pacific:

Any surviving debris should hit the planet within the hour, per Aerospace, but will we know?

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Update, April 1, 2018, 3:24 p.m. Pacific:

At the moment, the nonprofit company Aerospace guesstimates a reentry point somewhere off the western coast of South America, roughly two hours from now, but that is extremely iffy, as per the Space-com article linked below. The spacecraft is tumbling and many factors are working on it as it falls.

Here is Aerospace’s video of what the reentry might look like from space (they include actual footage of another craft’s reentry, taken from a plane–yes, it does look a little like the ending of Gravity, if Sandra Bullock had come down at night):

And here’s a little advice on what to do if you find a piece of Tiangong.

Just FYI: Space.Com is doing updates here.

Featured image: Craigboy via Wikimedia. CC BY-SA 3.0.

Mar 29 2018

Guest Video: Mars Update From NASA

The Curiosity rover passed its 2000-sol mark last week (1 sol = one Martian day, about 39 minutes longer than an Earth day). But the Opportunity rover–which was photographed from a spacecraft in orbit around Mars–has been going for over 5,000 sols!

This year’s InSight mission (launch scheduled for May 5, from Vandenburgh Air Force Base) is going to check out the Red Planet in depth. Here is more information about the 2020 mission.

Featured image: NASA/JPL-Caltech