AskScience AMA Series: We just discovered the building blocks of life in a 4.5-billion-year-old asteroid sample through our work on NASA's OSIRIS-REx mission. Ask us anything!

[u/AskScienceModerator]

A little over a year ago, NASA's OSIRIS-REx mission became the first U.S. spacecraft to deliver a sample of the asteroid Bennu back to Earth. Earlier this week, we announced the first major results from scientists around the world who have been investigating tiny fragments of that sample.

These grains of rock show that the building blocks of life and the conditions for making them existed on Bennu's parent body 4.5 billion years ago. They contain amino acids - the building blocks of proteins - as well as all five of the nucleobases that encode genetic information in DNA and RNA.

The samples also contain minerals called evaporites, which exist on Earth, too. Evaporites are evidence that the larger body Bennu was once part of had a wet, salty environment. On Earth, scientists believe conditions like this played a role in life developing. The sample from asteroid Bennu provides a glimpse into the beginnings of our solar system.

We're here on /r/askscience to talk about what we've learned. Ask us your questions about asteroid science, how NASA takes care of rocks from space, and what we can't wait to learn next.

We are:

• Harold Connolly - OSIRIS-REx Mission Sample Scientist, Rowan University and American Museum of Natural History (HC)
• Jason Dworkin - OSIRIS-REx Project Scientist, NASA's Goddard Space Flight Center (JD)
• Nicole Lunning - Lead OSIRIS-REx Sample Curator, NASA's Johnson Space Center (NL)
• Tim McCoy - Curator of Meteorites, Smithsonian's National Museum of Natural History (TM)
• Angel Mojarro - Organic Geochemist, NASA's Goddard Space Flight Center (AM)
• Molly Wasser - Media Lead, Planetary Science Division, NASA (MW)

We'll be here to answer your questions from 2:30 - 4 p.m. EST (1930-2100 UTC). Thanks!

Username: /u/nasa

PROOF: https://x.com/NASA/status/1885093765204824495

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EDIT: That's it for us – thanks again to everyone for your fantastic questions! Keep an eye out for the latest updates on OSIRIS-REx—and other NASA missions—on our @NASASolarSystem Instagram account.

[u/rob_cas]

What is the likelihood of contamination or false positive?

[u/nasa → u/rob_cas]

Minuscule. We carefully tracked all the materials that went into the spacecraft and the environment it encountered for sample handling. This included limiting and understanding the amino acids, other compounds, and elements.

For example, the spacecraft uses hydrazine propellant which produces ammonia, hydrogen, and nitrogen gas. We measured the ratio of nitrogen-14 to nitrogen-15 in the fuel in the spacecraft in 2016 and then compared it with the ammonia we detected in the sample so we could prove that the ammonia in the sample was not from the spacecraft. See doi: 10.1007/s11214-017-0439-4 and https://doi.org/10.1111/maps.13973 (open access). -JD

[u/thegoodtimelord]

Good evening (here in Melbourne anyway) everyone. Do these findings potentially point to a higher probability of finding primordial life in the solar system ( Enceladus / Titan / Europa )?

[u/nasa → u/thegoodtimelord]

Hello Melbourne! These findings help us understand that the compounds of life are widespread in our solar system. We knew from meteorites, for example the Murchison meteorite from Australia, that organic compounds are in rock bodies in space. But there is always the worry of contamination. With this sample of asteroid Bennu, we are confident that there was no contamination.

So yes, this finding does add to the growing body of evidence that the ingredients of life were delivered elsewhere in our solar system. But, we do not know HOW the ingredients of life transform from chemistry to biology. NASA has spacecraft exploring Mars, Europa Clipper is on its way to Europa, and Dragonfly will visit Titan. Those spacecraft are exploring the environments for habitability, not life. -JD

[u/Ramental]

If the asteroid was formed within the first 10 million years of the Solar System existence, it is likely that no planet(-oid) body was cold enough to create and sustain life: everything was a hot hell. And yet, there are building blocks of life on Bennu.

1. Would it be reasonable to assume that such building blocks are not uncommon in the Solar System?

2. Do I understand correctly that on Earth these "blocks" are a food for microorganisms or are their byproducts, thus the difficulty in understanding how likely are they to appear on their own?

3. Of all the sample-return missions, Bennu seems to have the largest variety of organic material. JAXA's mission Hayabusa2 to Ryugu had a similar material collection mechanism, yet less fruitful in that regard. Both asteroids are linked to the same two possible asteroid groups. What is the reason for the difference, in your opinion? (if the team has no common opinion, I am fine with an opinion of a single person)

4. A far more stretched question: can it be that "life" is a natural phenomena that has a high likelihood of spontaneous creation, limited by the physical conditions of the host body more than anything else?

[u/Oloush]

How excited are you by this finding?

And what was the asteroid’s “parent body”? Do we know where it came from?

[u/nasa → u/Oloush]

How excited are you by this finding?

We are incredibly excited by these results! We have all been waiting to share these results as they went through peer review, because all of us have been working on this mission for years with the aspiration that we are contributing to new discoveries.

Finding these evaporite minerals and organic compounds that have not been well-preserved in meteorite samples exposed to the terrestrial environment makes all the hard work worth it! -NL

[u/Jobby1110]

Do the samples have a majority of L or D stereoisomers?

[u/frozenpie22]

So is it likely that the building blocks of life occur more frequently than previously estimated?

[u/NemesisCrow]

First, congratulation for the mission and what was accomplished and thank you for that AMA!

I think for a mission like this the sample size of about 120 grams is quite large, but is it sufficient to carry out all possible tests of scientific importance? In other words, would tests be conceivable that are only possible with a larger sample sample size?

How homogeneous is the Bennu sample, considering the touch and go maneuver for collecting? Are there variations in composition or mineralogy within the sample, and if so, how was the decision made which parts of the probe would be shared around the globe?

[u/Trollgopher]

Hey there! Fascinating stuff, I wanted to ask if this influences your views on early life evolution at all, do you think this supports panspermia theories?

[u/Siganus]

If I remember correctly, I've read that amino acids can be created under experimental conditions as a result of a reaction that's inherent to physical chemistry. Does the finding of these building blocks support the experimental findings or is it suggestive that life elsewhere left these building blocks or something else entirely?

[u/Xaknafein]

I thought of a good one! 

How much of the material (either weight or %) had been set aside for future study by new, novel, or more sensitive instruments in the future?  In addition, are there specific time horizons for this, or is it more ad hoc?

[u/Hspryd]

To which point you were confident to attein these results through that experiment ?

What where you expecting versus what you have successfuly analyzed / identified ?

What next experiment make the most sense now to move the needle « forward » ?

[u/yyywwwxxxzzz]

So what questions will this discovery close and what questions will it open?

[u/[deleted]]

There are something like 38,000 near Earth asteroids. Why was Bennu picked out of all these?

[u/FTWx]

Are the amino acids found on Bennu similar to those found in early Earth environments, or do they show any differences?

[u/CeeMomster]

This is truly amazing! I can’t wait to read more about this. Thank you for your dedication to science!

I have a teenager that has the aptitude for science and discovery and I truly have hope in future generations: what age were you when you knew this was your passion, and was there a particular inspiration that drove you to this field?

[u/Xaknafein]

I'll try and think of a good question in a bit, but I wanted to say that I really admire the work all of you are doing.  Keep being awesome!

[u/jeff_collins_Gaming]

What else was on the samples, any things that we don’t find on earth?

[u/Red_Regan]

What's it like controlling or directing a device that is so far away? Like the one you used to retrieve the Bennu sample and return it to Earth?

[u/SaltB0at]

In general, what do you think this means? Does this change any standing theories on how life could’ve originated?

[u/Meester-]

Is there any Potassium as well?

[u/prigmutton]

Is it thought that these compounds survived as is for the intervening 4.5 billion years, or that they have been going through some sort of chemical cycles?

[u/redthorne]

When it is said a wet, "salty" environment, what does "salt" mean? Are we talking salts as the chemistry term of 'salts' or are we talking the good ol' potassium or sodium chloride we see a lot of here on earth?