Year: 2020

Study: Lava tubes on Mars and the Moon will be gigantic

9:34 am

A new study comparing lava tubes on the Earth with those detected from orbit on Mars and the Moon now suggests that tubes on those other worlds will be many times larger than on Earth.

Researchers found that Martian and lunar tubes are respectively 100 and 1,000 times wider than those on Earth, which typically have a diameter of 10 to 30 meters. Lower gravity and its effect on volcanism explain these outstanding dimensions (with total volumes exceeding 1 billion of cubic meters on the Moon).

Riccardo Pozzobon adds: “Tubes as wide as these can be longer than 40 kilometres, making the Moon an extraordinary target for subsurface exploration and potential settlement in the wide protected and stable environments of lava tubes. The latter are so big they can contain Padua’s entire city centre”.

Moreover, the data suggests their roofs, even at this size, will be very stable because of the lower gravity, making them excellent locations for large human colonies.

The researchers also suggest that there are many intact such lava tubes under the mare regions on the Moon, their existence only hinted at by the rare skylights created due to asteroid impact.

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SpaceX and ULA get launch contracts from SES

9:28 am

Capitalism in space: The satellite communications company SES yesterday announced the award of new launch contracts to both SpaceX and ULA.

It appears that the contract was for one launch from each company, each putting up two satellites. Previously SES’s satellites were generally too large for either the Atlas 5 or the Falcon 9 to launch two at one time. This suggests that the satellite company is slimming down the design of its satellites.

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Jeff Bezos sells $3 billion more in Amazon stock

9:23 am

Jeff Bezos this week sold another $3 billion in his Amazon stock, bringing the sales this year along to more than $7 billion.

Amazon stock has soared since mid-March as millions of customers rely on the e-commerce giant amid the pandemic for online shopping, cloud computing, and more. Last week the company posted $88.9 billion in revenue, up 40% from the year-ago quarter, with profits far ahead of Wall Street expectations at $5.2 billion.

Bezos said in 2017 that he was selling $1 billion a year to fund his Blue Origin space venture, but he has been increasing the size and frequency of the stock sales. He sold $2.8 billion worth of Amazon stock a year ago, and around $4 billion earlier this year.

Since 2017 Bezos has now raised more than $11 billion from sales of his Amazon stock. Initially he had said such sales were to finance his space company Blue Origin, but more recently he has indicated he wants to use the bulk of this cash to fight climate change, with portions also devoted services for the homeless and early childhood education.

In fact, it appears that Blue Origin is likely getting only a very small portion of this money, though at several billion this isn’t chicken-feed. At a minimum it likely matches what SpaceX has raised through private investment capital for its Starship/Starlink projects, and more likely exceeds it.

Yet, SpaceX continues to outpace Blue Origin, several times over. If anything, as the cash from Bezos has rolled in Blue Origin’s pace of test flights with New Shepard as well as the development of its BE-4 rocket engine and New Glenn orbital rocket seemed have slowed. Initially New Glenn was going to make its first orbital launch this year. Now they say it will launch next year but we hear little about any development progress. And the company only delivered a test engine of the BE-4 (not flight worthy) to ULA only about a month ago, far later than first promised.

Though the lack of news could simply be Blue Origin’s more secretive way of doing things, compared to SpaceX, I have my doubts. Rockets are big things, and building and testing them is not something easily kept under wraps, especially by private companies. The lack of news from Blue Origin continues to suggest that simply having lots of money does not necessarily guarantee success.

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Astronomers use Hubble to detect ozone on Earth

8:57 am

Using the Hubble Space Telescope, scientists have shown that it will be possible to detect ozone in the atmospheres of exoplanets, using larger telescopes while observing transits of those exoplanets across the face of their star.

What the scientists did was aim Hubble at the Moon during a lunar eclipse. Moreover, they timed the observations so that the sunlight hitting the Moon and reflecting back to Earth (and Hubble) had also traveled through the Earth’s atmosphere on its way to the Moon.

They then looked at the spectrum of that light, and were able to glean from it the spectral signal of ozone in the Earth’s atmosphere. When giant ground-based telescopes under construction now come on line in the coming decades they will have the ability to do this with transiting exoplanets.

The measurements detected the strong spectral fingerprint of ozone, a key prerequisite for the presence – and possible evolution – of life as we know it in an exo-Earth. Although some ozone signatures had been detected in previous ground-based observations during lunar eclipses, Hubble’s study represents the strongest detection of the molecule to date because it can look at the ultraviolet light, which is absorbed by our atmosphere and does not reach the ground. On Earth, photosynthesis over billions of years is responsible for our planet’s high oxygen levels and thick ozone layer. Only 600 million years ago Earth’s atmosphere had built up enough ozone to shield life from the Sun’s lethal ultraviolet radiation. That made it safe for the first land-based life to migrate out of our oceans.

“Finding ozone in the spectrum of an exo-Earth would be significant because it is a photochemical byproduct of molecular oxygen, which is a byproduct of life,” explained Allison Youngblood of the Laboratory for Atmospheric and Space Physics in Colorado, USA, lead researcher of Hubble’s observations.

Ozone does not guarantee the presence of life on an exoplanet, but combined with other detections, such as oxygen and methane, would raise the odds significantly.

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Filled and distorted craters on Mars

9:12 pm

A very distorted and filled crater on Mars
Click for full image.

Cool image time! The photo to the right, rotated and cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on May 25, 2020. The entire image was dubbed “Cluster of Filled Craters”, but I decided to highlight the crater of the cluster that was most strangely distorted of them all. The material that fills all the craters in the full image is almost certainly buried ice and is dubbed concentric crater fill by scientists.

This crater is located in the northern lowland plains the mid-latitudes between 30 and 60 degrees, where planetary scientists have found ample evidence of many such filled craters and glaciers.

Not only does the crater’s interior seemed filled with glacial material, its distorted rim suggests that it has been reshaped by glacial activity that might have covered it entirely over the eons as the mid-latitude glaciers of Mars waxed and waned with the extreme shifts that happen regularly to Mars’ rotational tilt. Moreover, there is strong evidence that in these lowland northern plains an underground ice table exists close to the surface, allowing for more distortion over time.

The overview map below provides some location context.
» Read more

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Lightning and mushballs on Jupiter

3:49 pm

Artist's illustration of Jupiter lightning
Click for full illustration.

Using data from Juno, scientists now theorize that Jupiter produces what they dub “shallow lightning” as well as ammonia-water hailstones dubbed “mushballs.”

The image to the right, cropped and reduced to post here, is only an artist’s illustration of the lightning. Sadly Juno’s camera doesn’t have the resolution to capture such flashes.

An unexpected form of electrical discharge, shallow lightning originates from clouds containing an ammonia-water solution, whereas lightning on Earth originates from water clouds.

Other new findings suggest the violent thunderstorms for which the gas giant is known may form slushy ammonia-rich hailstones Juno’s science team calls “mushballs”; they theorize that mushballs essentially kidnap ammonia and water in the upper atmosphere and carry them into the depths of Jupiter’s atmosphere.

As with the InSight results below, there is much uncertainty with these results, especially the hypothesis of mushballs. These features fit their present data from Juno, but we must remember that the data is still somewhat superficial.

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Scientists make first rough estimate of Mars’ internal structure

3:33 pm

Artist's cutaway showing theorized Martian interior
Artist’s cutaway of theorized Martian interior

Using data from InSight’s seismometer, scientists have made their first approximation of the internal structure of Mars.

The first boundary Deng and Levander measured is the divide between Mars’ crust and mantle almost 22 miles (35 kilometers) beneath the lander.

The second is a transition zone within the mantle where magnesium iron silicates undergo a geochemical change. Above the zone, the elements form a mineral called olivine, and beneath it, heat and pressure compress them into a new mineral called wadsleyite. Known as the olivine-wadsleyite transition, this zone was found 690-727 miles (1,110-1,170 kilometers) beneath InSight. “The temperature at the olivine-wadsleyite transition is an important key to building thermal models of Mars,” Deng said. “From the depth of the transition, we can easily calculate the pressure, and with that, we can derive the temperature.”

The third boundary he and Levander measured is the border between Mars’ mantle and its iron-rich core, which they found about 945-994 miles (1,520-1,600 kilometers) beneath the lander. Better understanding this boundary “can provide information about the planet’s development from both a chemical and thermal point of view,” Deng said.

Because they only have one seismometer on the planet, this approximation has a great deal of uncertainty. Only when we have multiple such seismic instruments, scattered across the entire Martian globe, will scientists be able to hone their models more accurate of the planet’s interior.

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Out hiking

8:02 am

Posting will resume this afternoon. Diane wanted to do a mid-week hike and I needed desperately to get out. The gyms are closed, you can’t go anywhere without being accosted for not wearing a mask, and the news is just too depressing.

In the mountains you can at least make believe you can still breathe free in America.

We should be back by 2 pm (Pacific). I will begin posting then.

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