Astronomy & Space Exploration

Holy shit they actually caught the booster first time. Unbelievable to watch.
 
Feck SpaceX, probably most important NASA mission in ages about to launch
 
nimic said:
It's great news if true, but they also say it's 10-20 km below the crust. It may very well be easier to use the water we already know about on the surface (even if it isn't in liquid form).
Click to expand...
Get Bruce Willis and Ben Affleck on the phone.
 
There was an excellent sci fi film about this. Spoiler: it doesn't go great when we sent people to Europa.
 
Shows my age, I thought the reference was to 2010: Odyssey 2 where Jupiter gets turned into star for the benefit of the native Europans.
 
https://www.bbc.co.uk/news/articles/c140exemgk7o

Nice article on a star that brightens every eighty years and goes from very dim to visible to the naked eye - but only for a couple of days. Due to happen "soon".

It features an interview with a chap who spotted the brightened star 80 years ago and reported the sighting to the astromener royal - who replied.

He's now hoping that someone will take him to a good spot to see it this time around.
 
Good stuff. Cheers, @jojojo!

Back in the day, I was a bit disappointed to learn that the Blaze Star system (much prefer this name to T Corona Borealis) doesn't possess the mass to to go supernova. :(

At a distance of ~3,000 light-years, a type Ia supernova would've been close enough to be an extremely prominent feature in the skies (and make up for us missing out on the supernovae that ultimately created the Jellyfish and Crab nebulae).

Then again, being bathed in raditation wouldn't have been so nice (“danger zone” for type Ia supernovae is estimated to be in the ~3,200 light-years range, so better safe than sorry).
 
nimic said:
Is that correct? Surely you use the word "danger" loosely here?
Click to expand...
No, that's correct, but only along the rotation axis where a gamma ray burst can happen. Which is an event that's suspected to be the reason for at least one of the big mass extinctions in earth history (late Ordovician).
 
nimic said:
Is that correct? Surely you use the word "danger" loosely here?
Click to expand...
Oh, I wish I was using the word “danger” loosely! :o

For reference, 1 parsec ~ 3.26 light-years.
This is significant -- a type Ia SN, at the distance of 1000 pc, dumps as much gamma-ray radiation onto the earth as 1,000 solar flares. Even when the Sun is at the peak of its activity cycle, I don't think it flares ten times a day, so, even at a kiloparsec, a type Ia SN would outshine the Sun in gamma rays. However, while I do know that we easily survive even the greatest solar flares, I don't know how a large increase in the gamma-ray flux over a period of several months would affect the earth's atmosphere.

Steve Thorsett, in a preprint "Terrestial Implications of Cosmological Gamma-Ray Burst Models," quotes sources which suggest that considerably more than 100,000 erg/(cm^2) in gamma-rays are needed to destroy the ozone layer, so it seems that a type Ia would have to be closer than 1 kpc to cause significant damage.
Click to expand...
http://spiff.rit.edu/richmond/answers/snrisks.txt

In some cases, you can even get a steady dose of short-duration bursts of heightened radiation, beyond the initial longer-duration burst(s) of heightened radiation.
 
Invictus said:
Oh, I wish I was using the word “danger” loosely! :o

For reference, 1 parsec ~ 3.26 light-years.

http://spiff.rit.edu/richmond/answers/snrisks.txt

In some cases, you can even get a steady dose of short-duration bursts of heightened radiation, beyond the initial longer-duration burst(s) of heightened radiation.
Click to expand...

Only astronomers would still use http. That's how I know the source is reliable (even if I won't click on it).

Edit: though that source does seem to say it wouldn't be... you know, apocalyptic. So that's nice.
 
stefan92 said:
No, that's correct, but only along the rotation axis where a gamma ray burst can happen. Which is an event that's suspected to be the reason for at least one of the big mass extinctions in earth history (late Ordovician).
Click to expand...

I don't think gamma-ray bursts are from Type Ia supernova. Aren't they from a different kind of supernova? A gamma-ray burst would certainly wreck the Earth from 3k light years. Anywhere within the galaxy, really, as long as it's aimed at us.
 
nimic said:
Edit: though that source does seem to say it wouldn't be... you know, apocalyptic. So that's nice.
Click to expand...
It wouldn't be an event that sterilizes the Earth or something along those lines by any means, even if you add the mass required to exceed the Chandrasekhar Limit and result in a Type Ia supernova. For sterilization, the Blaze Star system would have to be more proximitous or you would need a more massive Type II supernova where a relativistic jet is aligned with an unfortunate Earth (even at a much greater distance). But it could still cause disturbances in the ionosphere and unnecessarily damage the ozone layer, and expose all manners of life on Earth to harmful radiation. The juice (i.e., temporary gratification and priviledge of being able to witness an extremely prominent feature in the skies) is not worth the squeeze (i.e, elevated threat of harmful radiation endangering a myriad lifeforms on Earth, even if it doesn't result in an apocalypse). Nooo, sir!
 
Invictus said:
Good stuff. Cheers, @jojojo!

Back in the day, I was a bit disappointed to learn that the Blaze Star system (much prefer this name to T Corona Borealis) doesn't possess the mass to to go supernova. :(

At a distance of ~3,000 light-years, a type Ia supernova would've been close enough to be an extremely prominent feature in the skies (and make up for us missing out on the supernovae that ultimately created the Jellyfish and Crab nebulae).

Then again, being bathed in raditation wouldn't have been so nice (“danger zone” for type Ia supernovae is estimated to be in the ~3,200 light-years range, so better safe than sorry).
Click to expand...
I've not heard of a binary nova that isn't a type 1A, and is periodical
 
How big is this SphereX telescope, in terms of the types of pictures it will send back? Not really heard any excitement about it in the way there was with James Webb (ie being covered in mainstream news so the likes of me sees it and gets interested).



Piece in the Times on it:
The SphereX observatory (Spectro-Photometer for the History of the Universe, Epoch of Reionisation and Ices Explorer) will create a 3D map of more than 100 million stars in the Milky Way and 450 million galaxies beyond.
Click to expand...
https://www.thetimes.com/us/news-today/article/nasa-spherex-punch-launch-qvhvgjnzt
 
Jippy said:
How big is this SphereX telescope, in terms of the types of pictures it will send back? Not really heard any excitement about it in the way there was with James Webb (ie being covered in mainstream news so the likes of me sees it and gets interested).
Click to expand...
It's completely different. It only has a 20cm telescope, while JWST has 6.5m, and it won't really create pictures in the classic sense but scan the whole sky.

SphereX is more of a little brother to Euclid https://en.m.wikipedia.org/wiki/Euclid_(spacecraft)
 

Researchers analyzing pulverized rock onboard NASA’s Curiosity rover have found the largest organic compounds on the Red Planet to date. The finding, published Monday in the Proceedings of the National Academy of Sciences, suggests prebiotic chemistry may have advanced further on Mars than previously observed.

Scientists probed an existing rock sample inside Curiosity’s Sample Analysis at Mars (SAM) mini-lab and found the molecules decane, undecane, and dodecane. These compounds, which are made up of 10, 11, and 12 carbons, respectively, are thought to be the fragments of fatty acids that were preserved in the sample. Fatty acids are among the organic molecules that on Earth are chemical building blocks of life.

Living things produce fatty acids to help form cell membranes and perform various other functions. But fatty acids also can be made without life, through chemical reactions triggered by various geological processes, including the interaction of water with minerals in hydrothermal vents.

While there’s no way to confirm the source of the molecules identified, finding them at all is exciting for Curiosity’s science team for a couple of reasons.

Curiosity scientists had previously discovered small, simple organic molecules on Mars, but finding these larger compounds provides the first evidence that organic chemistry advanced toward the kind of complexity required for an origin of life on Mars.

The new study also increases the chances that large organic molecules that can be made only in the presence of life, known as “biosignatures,” could be preserved on Mars, allaying concerns that such compounds get destroyed after tens of millions of years of exposure to intense radiation and oxidation.

This finding bodes well for plans to bring samples from Mars to Earth to analyze them with the most sophisticated instruments available here, the scientists say.

“Our study proves that, even today, by analyzing Mars samples we could detect chemical signatures of past life, if it ever existed on Mars,” said Caroline Freissinet, the lead study author and research scientist at the French National Centre for Scientific Research in the Laboratory for Atmospheres and Space Observations in Guyancourt, France

In 2015, Freissinet co-led a team that, in a first, conclusively identified Martian organic molecules in the same sample that was used for the current study. Nicknamed “Cumberland,” the sample has been analyzed many times with SAM using different techniques.

Curiosity drilled the Cumberland sample in May 2013 from an area in Mars’ Gale Crater called “Yellowknife Bay.” Scientists were so intrigued by Yellowknife Bay, which looked like an ancient lakebed, they sent the rover there before heading in the opposite direction to its primary destination of Mount Sharp, which rises from the floor of the crater.

The detour was worth it: Cumberland turns out to be jam-packed with tantalizing chemical clues to Gale Crater’s 3.7-billion-year past. Scientists have previously found the sample to be rich in clay minerals, which form in water. It has abundant sulfur, which can help preserve organic molecules. Cumberland also has lots of nitrates, which on Earth are essential to the health of plants and animals, and methane made with a type of carbon that on Earth is associated with biological processes.

Perhaps most important, scientists determined that Yellowknife Bay was indeed the site of an ancient lake, providing an environment that could concentrate organic molecules and preserve them in fine-grained sedimentary rock called mudstone.

“There is evidence that liquid water existed in Gale Crater for millions of years and probably much longer, which means there was enough time for life-forming chemistry to happen in these crater-lake environments on Mars,” said Daniel Glavin, senior scientist for sample return at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a study co-author.

The recent organic compounds discovery was a side effect of an unrelated experiment to probe Cumberland for signs of amino acids, which are the building blocks of proteins. After heating the sample twice in SAM’s oven and then measuring the mass of the molecules released, the team saw no evidence of amino acids. But they noticed that the sample released small amounts of decane, undecane, and dodecane.

Because these compounds could have broken off from larger molecules during heating, scientists worked backward to figure out what structures they may have come from. They hypothesized these molecules were remnants of the fatty acids undecanoic acid, dodecanoic acid, and tridecanoic acid, respectively.

The scientists tested their prediction in the lab, mixing undecanoic acid into a Mars-like clay and conducting a SAM-like experiment. After being heated, the undecanoic acid released decane, as predicted. The researchers then referenced experiments already published by other scientists to show that the undecane could have broken off from dodecanoic acid and dodecane from tridecanoic acid.

The authors found an additional intriguing detail in their study related to the number of carbon atoms that make up the presumed fatty acids in the sample. The backbone of each fatty acid is a long, straight chain of 11 to 13 carbons, depending on the molecule. Notably, non-biological processes typically make shorter fatty acids, with less than 12 carbons.

It’s possible that the Cumberland sample has longer-chain fatty acids, the scientists say, but SAM is not optimized to detect longer chains.

Scientists say that, ultimately, there’s a limit to how much they can infer from molecule-hunting instruments that can be sent to Mars. “We are ready to take the next big step and bring Mars samples home to our labs to settle the debate about life on Mars,” said Glavin.
Click to expand...
 
Buster15 said:
The chances of anything coming from Mars is a million to one......
Click to expand...

The life on Mars thing is not quite as interesting as it once was before thousands of exoplants were discovered over the past decade or two. Its become obvious that there are trillions of planets out there (possibly in this galaxy alone) and there will be some form of life on a small percentage of those in the habitable zone.
 
Raoul said:
The life on Mars thing is not quite as interesting as it once was before thousands of exoplants were discovered over the past decade or two. Its become obvious that there are trillions of planets out there (possibly in this galaxy alone) and there will be some form of life on a small percentage of those in the habitable zone.
Click to expand...
That is a very interesting prospect isn't it.
 
Raoul said:
The life on Mars thing is not quite as interesting as it once was before thousands of exoplants were discovered over the past decade or two. Its become obvious that there are trillions of planets out there (possibly in this galaxy alone) and there will be some form of life on a small percentage of those in the habitable zone.
Click to expand...

But Mars is the only planet that will ever have the possibility of human colonisation. Finding evidence of life on planets that no human or robot will ever set foot on is not as big a deal as finding life on Mars, especially microbial life. Finding life on planets tens of lightyears away is nice but it won't make much of a difference as there will never be any form of contact between us and them.
 
The holy trinity 68 said:
But Mars is the only planet that will ever have the possibility of human colonisation. Finding evidence of life on planets that no human or robot will ever set foot on is not as big a deal as finding life on Mars, especially microbial life. Finding life on planets tens of lightyears away is nice but it won't make much of a difference as there will never be any form of contact between us and them.
Click to expand...
Colonising Mars is kind of a "side quest" for humanity at best. It's not ideal, it is relatively small, it is cold, it doesn't have the atmosphere and/or magnetic field to protect humans... Not a single one of humanity's issues can be fixed by colonising Mars.
 
Buster15 said:
That is a very interesting prospect isn't it.
Click to expand...

Indeed. We often think of life elsewhere as being far more advanced than humans, but wouldn't it be something if a vast majority of it was primitive by our standards with little hope of advancing because natural selection may not quite work as well on other worlds.
 
The holy trinity 68 said:
But Mars is the only planet that will ever have the possibility of human colonisation. Finding evidence of life on planets that no human or robot will ever set foot on is not as big a deal as finding life on Mars, especially microbial life. Finding life on planets tens of lightyears away is nice but it won't make much of a difference as there will never be any form of contact between us and them.
Click to expand...

Even if there is microbial life left over from ancient below ground Martian oceans, it wouldn't be particularly useful to us if we are planning on one day colonizing Mars, which would happen anyway with or without the discovery of previous life there. Humans would have to create a brand new ecosystem of life based on human technology of the present and future. On the other hand, if we discover water sources below the surface, it could be a game changer in terms of colonization prospects.
 
stefan92 said:
Colonising Mars is kind of a "side quest" for humanity at best. It's not ideal, it is relatively small, it is cold, it doesn't have the atmosphere and/or magnetic field to protect humans... Not a single one of humanity's issues can be fixed by colonising Mars.
Click to expand...
Short term, Mars colonisation is an expensive waste. Long term, it will be vital.

But I do accept the time periods often get drastically understated.
 
rcoobc said:
Short term, Mars colonisation is an expensive waste. Long term, it will be vital.

But I do accept the time periods often get drastically understated.
Click to expand...

Yeah, I don't think Mars colonization will become viable for another 30-50 years. Once we are regularly sending humans back and forth from the moon, establishing permanent bases there as a precursor to what it may be like to attempt something similar on the moon, then it may be worth taking a legitimate shot at going to Mars.

We're not going to be running out of land on earth anytime soon, so it won't be an issue for decades imo.
 
stefan92 said:
Genuine question: Why? Why will colonising Mars become vital for humanity?
Click to expand...

Presumably because humans will eventually run out of land and resources. We are at about 8 billion people now and once the population grows by a few billion more, resources will become increasingly scarce. Although who knows how things will unfold with AI now in the mix.
 
Raoul said:
Even if there is microbial life left over from ancient below ground Martian oceans, it wouldn't be particularly useful to us if we are planning on one day colonizing Mars, which would happen anyway with or without the discovery of previous life there. Humans would have to create a brand new ecosystem of life based on human technology of the present and future. On the other hand, if we discover water sources below the surface, it could be a game changer in terms of colonization prospects.
Click to expand...

True but finding life on Mars is much easier than finding signs of life 200 light years away and finding microbial life itself is a massive deal.
 
Raoul said:
Presumably because humans will eventually run out of land and resources. We are at about 8 billion people now and once the population grows by a few billion more, resources will become increasingly scarce. Although who knows how things will unfold with AI now in the mix.
Click to expand...
Mars has about 11% of the surface of Earth. I agree that it would be helpful, but 11% more space won't be vital in my opinion. And yes I did include the oceans and the (ant)arctic regions, because those are still far more habitable than anything on Mars.
 
The holy trinity 68 said:
True but finding life on Mars is much easier than finding signs of life 200 light years away and finding microbial life itself is a massive deal.
Click to expand...

To what end though? We can deduce that any planet within the habitable zone of this or other solar systems may in very small percentages have some form of primitive life - especially where water is present. It wouldn't be of any help to us since even if there were fossilized ancient microbial life deep within ancient dried up Martian ocean beds, we would still need to create a world humans could live within on Mars using mostly human technology.
 
You must log in or register to reply here.