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Axios' NASA emails reveal agency's surprise at asteroid's near-miss of Earth cites Buzzfeed's A “Sneaky” Asteroid Narrowly Missed Earth This Summer. Internal Emails Show How NASA Scientists Totally Missed It. which links to the resulting huge (~100 MB) PDF of the response to their FOIA request.

Part of the Axios summarization:

Internal NASA communications show the agency's surprise after a football-field-sized asteroid narrowly missed Earth in July, according to emails acquired by BuzzFeed News via a Freedom of Information Act request.

Why it matters: The emails show that NASA officials believe the agency is lacking necessary infrastructure to reliably detect asteroids.

Context: The asteroid, called "2019 OK," passed about 40,400 miles above Earth's surface — roughly 5 times closer to Earth than the moon — at 55,000 miles per hour and could have "created localized devastation to an area roughly 50 miles across" if it struck land, according to a NASA news release.

The big picture: "The near-miss of the incoming asteroid points to a long-running fight between NASA and Congress to build a reliable way to watch for 'potentially hazardous' asteroids," writes BuzzFeed.

NASA relies on lawmakers to fund telescopes and spacecraft that can detect near-Earth objects.

What they said: In an email acquired by BuzzFeed, Lindley Johnson, NASA's planetary defense officer, wrote, "This one did sneak up on us and it is an interesting story on the limitations of our current survey network."


Question: What is the "interesting story on the limitations of (NASA's) current survey network", or what is it most likely to be?

Quotes in the lengthy Buzzfeed article mention the speed of the apparent motion of the asteroid with respect to the stars, I'm wondering if there are certain NEO orbits that are particularly challenging to the automatic algorithms that analyze images.

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    $\begingroup$ I think I don't entirely understand the question. To me it sounds like the 'interesting story' simply is that they missed the asteroid until 24h to go. And this is an example of their limited detection capabilities. $\endgroup$ – user2705196 Sep 20 '19 at 13:23
  • $\begingroup$ @user2705196 I have a hunch that the reason they missed this one will turn out to be very interesting. Have a look at my last sentence, then the Buzzfeed article, then the PDF. $\endgroup$ – uhoh Sep 20 '19 at 15:00
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    $\begingroup$ Nothing that exciting or scandalous. It was too faint in June to be detected by the automatic algorithms of PS1 against detector and the Full Moon, bad weather and the flyby geometry producing an extra slow apparent motion below the threshold of automatic moving object code resulted in a late detection. There are a lot of very small NEOs, some are going to come from directions or times that make them hard to observe. $\endgroup$ – astrosnapper Sep 20 '19 at 18:39
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    $\begingroup$ Strongly recommend this article by the Planetary Society on the state of NEO detection $\endgroup$ – astrosnapper Sep 20 '19 at 18:51
  • $\begingroup$ @astrosnapper I'll give it a read today, thanks! $\endgroup$ – uhoh Sep 20 '19 at 22:59
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For years, wide field infrared orbital telescopes have been touted as the best way to complete a survey of NEO objects and give a greater warning time on potential close approaches. Astronsapper's Plantetary Society article talks about this partially. For years, proposals have been put forth to build these orbiting telescopes, but there is not a strong pure science function that they can fulfill, so these telescopes do not fare well in evaluations against missions that are targeted to make specific scientific discoveries. Congress has not directed NASA to set aside earmarked funding for this effort, so the agency finds itself hamstrung by its science focused evaluation criteria and thus the systems to map all the NEO's do not get built. If we want to change this situation, we have to start with getting our congressional representatives to give the appropriate funding and direction to NASA.

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  • $\begingroup$ I should point out that WFIRST has some capability in this area when it launches, and NEOWISE did quite a bit of work while its coolant lasted, but "Defending Planet Earth" by the National Academy's Press talks in depth about the fact that neither instrument is optimized for finding the numerous small NEO's that are harder to spot in the visible range. nap.edu/download/12842 $\endgroup$ – Terrance Yee Aug 3 at 22:09
  • $\begingroup$ Thank you very much for your answer! This is certainly an interesting story but we may never be sure that this is the interesting story that Johnson was thinking of when that sentence was written. There still may be an orbital-mechanically interesting story relating to the specific corridor through which the object approached and how that particular object has remained undetected beyond the inadequate concern of congress and their dereliction of their duty to protect us. $\endgroup$ – uhoh Aug 4 at 1:08
  • $\begingroup$ A quick search of the 100 MB PDF linked in my question for terms like "sneak" and "cuts" provides some interesting perspective $\endgroup$ – uhoh Aug 4 at 1:15
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    $\begingroup$ One additional "interesting" possibility, is that the GEO belt may be off limits to routine telescope operations to avoid collecting sensitive intelligence (and ruining a lot of otherwise great astronomy pictures with dumb satellite flares). If this object was travelling in this plane when it was on close approach, then it may have slipped between the net. $\endgroup$ – Terrance Yee Aug 20 at 0:40
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    $\begingroup$ If I were an alien looking to sneak up on Earth I might follow the approach vector that hides in the "local" traffic. I've read some SciFi stories where the aliens use the Moon for cover, but that only gets you so far. Other stories have the aliens coming from the sunward direction, but I'll bet that's a difficult powered trajectory to fly from an energy standpoint. $\endgroup$ – Terrance Yee Aug 20 at 1:12

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