3992

They may have jumped the gun in announcing the Venus-phosphine detection.

https://www.nationalgeographic.com/science/2020/10/venus-might-not-have-much-phosphine-dampening-hopes-for-life/

These mistakes do happen in difficult signal detection problems, but I bet the guy who spent a year calculating the expected phosphine contributions from known non-biological sources for phosphine in the Venusian atmosphere is a little put out.

3993

I still think it would be cool to float around Venus in a dirigible.

3994

https://www.washingtonpost.com/science/2020/10/26/water-on-the-moon/

3995

Non paywalled source: https://www.nasa.gov/press-release/nasa-s-sofia-discovers-water-on-sunlit-surface-of-moon/

3996

Hubble finds and asteroid that’s all metal and is worth quadrillions in Earth money.

The article says it’s the size of West Virgina but also says it’s 14 miles across the surface. Is West Virgina that small?

3997

If its diameter is 140 miles and it’s roughly spherical (it isn’t, but rough estimate) then it has a surface area of 20.6 million square miles, which is actually slightly smaller than West Virginia’s area (24 million square miles.)

I hate when they put dollar amounts on those things. There’s no way to mine asteroids for use on Earth. And even if they could–that asteroid has something like 100,000,000 times more metal than is mined annually globally here on Earth. There’s no economic equation that permits estimating costs when you disrupt a market to that tune.

3998

But it makes for a good clickbait headline!

3999

Well, if we smash it INTO West Virginia, we can get at the metal! Right? Right?

4000

Given that Psyche 16 is about 100x more massive than the Chicxulub impactor was, we could get at all of the metal. All of it.

4001

They could drop the metal a little bit at a time instead of all at once.

4002

The problem with even theoretically moving this to orbit near earth should be obvious. And the logistics of mining it in place are impossible for now.

It’s cool, but I doubt it becomes more than that ever.

4003

Maybe we could put a little parachute on it.

/s

4004

Oh, yeah, it’s firmly in the realm of science fiction right now. Theoretically, asteroids are the logical place to go for metals eventually, but getting there (literally and figuratively) ain’t easy.

4005

That said if we wanted to build on another planet, loping off a hunk and depositing it on site would be better. You want to crash a few billion tons of metal onto the moon? well fine. I just wouldn’t want anything larger than about 10m diameter (approximate size of iron asteroid that would reach the earths surface) sent within anything approaching inside the lunar orbit.

I mean there are scientific costs to dropping a huge hunk of metal onto Mars or the moon, but from the perspective of ‘hey why don’t we drop a few million tons of iron onto a land mass’ it has far fewer downsides.

4006

If you are building in a gravity well, be it Earth, Mars or the Moon, probably much easier/cheaper to mine locally than to grab minerals from an asteroid. But if you are doing the Bezos thing of building thousands of huge space habitats scattered across the solar system this might be a relatively inexpensive source of certain raw materials.

4007

Well you have to be careful about ramming stuff into the Moon I guess, at least that’s what I learned from Seven-eve.

4008

Turns out Dark Matter is just… regular matter that’s dim.

4009

I can’t tell from the article, but I don’t think that discovery is about dark matter; it’s about missing amounts of “regular” matter.

4010

I mean, here’s the actual paper, which is (I think) about detecting previously undetectable x-ray regimes in cosmic filaments and says nothing about dark matter at all.

https://www.aanda.org/articles/aa/full_html/2020/11/aa38521-20/aa38521-20.html

Using the stacked X-ray count rate measured at the ROSAT six energy bands, we perform an X-ray spectral analysis with the APEC model and estimate the average gas density and temperature at the cores (<2 Mpc) of the filaments. We find that the average central overdensity is δ = 30 ¹ 15, assuming a cylindrical filament with a density distribution following a β -model with β = 2/3. We compare our measurement of gas density with other statistical measurements with the weak-lensing and the tSZ, and find that they are all consistent. We also estimate the average gas temperature in the filament core region to be keV and find that it is a bit larger than the study of gas in large cosmic filaments with the tSZ by T20. This may imply that the gas temperature is higher at the cores compared to the outskirts, considering that the gas temperature from X-rays is estimated in a region < 2 Mpc from the filament spines whereas the values in the tSZ measurements are the average beyond the distance (∟5 Mpc).

EDIT: And here’s CNRS’s press release.

Galaxies are distributed throughout the Universe in the form of a complex network of nodes connected by filaments, which are in turn separated by voids. This is known as the cosmic web. The filaments are thought to contain almost all of the ordinary (so-called baryonic) matter of the Universe in the form of a diffuse, hot gas. However, the signal emitted by this diffuse gas is so weak that in reality 40 to 50% of the baryons1 goes undetected.

These are the missing baryons, hidden in the filamentary structure of the cosmic web, that Nabila Aghanim, a researcher at the Institut d’Astrophysique Spatiale (CNRS/Université Paris-Saclay) and Hideki Tanimura, a post-doctoral researcher, together with their colleagues, are attempting to detect.

4011

It’s times like this when I wish I had taken more STEM courses in college, especially physics. I’d love to really understand it.