Exposing PseudoAstronomy

January 10, 2016

Some Real Science: Lots of Grunt Work, Moon Craters


Over the last few days, I’ve been hunkering down due to the deadline for abstract submission to the premier planetary science conference, the Lunar and Planetary Science Conference. It’s held annually in March in Houston, TX. Everyone is allowed to submit up to two first-author abstracts, and I have, for the last couple years, done two. This year’s not an exception. I’ll post about my New Horizons -related one later.

This post is about my abstract entitled, “Developing a Global Lunar Crater Database, Complete for Craters ≥1 km.” Because the file sizes have to be <1 MB, the figures are low resolution.

There are many, many different purposes to conferences, though the primary is “communication with colleagues.” Within that are many different things, like talking about your research and getting ideas. Another is to be able to show colleagues what you are doing so that, if your name happens to come in, say, a grant application, they might just recognize it.

For LPSC this year, my non-New Horizons abstract is in that category. I’m setting myself up for writing a grant later this year to build a lunar crater catalog that contains a lot of information about roughly 1 million craters on the moon. It’s been rejected for a couple years, and one of the underlying reasons is that I don’t know how many craters there are, therefore I can’t give a good, accurate work effort estimate to do all the information-gathering about each crater.

This abstract is meant to answer part of that. I’ve been leveraging bits and pieces of funding from different sources over the last year to do the initial mapping part — identifying the craters and locating them and measuring their diameters. For this abstract, I’ve roughly 28% of the moon done. For the March conference, I’m hoping to be closer to 50%, and by the time the grants are due this autumn, 100% so I know how many craters I have to do more stuff with.

Two more things I want to talk about in this slightly longer post. First is grunt work. Science is not easy. Science is rarely glamorous. Science is sitting down and 99% of what you do no one will ever know about because it’s only the results – not that big data-gathering process – that form the bulk of your paper. Methods sections are usually <25% of a paper because relatively few people care about that in comparison with your results.

And trust me, sitting down and drawing circles for hundreds of hours on end is NOT glamorous. But the results are cool.

Second is why we care – why are the results "cool." One reason is that it just looks cool — seeing all those dots that indicate a crater, and seeing all the patterns that emerge tell us a lot about the different history of those areas of the moon. The main one is ages (more craters = older). But we can also do things like better understand what's hit the moon in the past, and hence what is likely to hit Earth in the future. We can study different materials even, which is why the second figure is devoted to permanently shadowed regions where there might be water (areas that never see the sun act as cold traps for water molecules).

Anyway, this is turning out longer than I wanted, so to wrap it up … that's one thing that has been occupying a lot of my time over the last few days. One down, one to go.

September 9, 2015

Podcast Episode 140: Doomsmonth— September 2015


Doomsmonth: September.
What could it bring that hasn’t
Yet been wrought on Earth?

Are we all gonna die this month? You’ll need to listen to the episode to find out. I’ve heard lots of rumors floating around about various things causing our doom, and in this episode, I go through five of them and assess their validity and background.

The logical fallacies segment presents two logical fallacies: Correlation ≠ causation, and cherry picking. Otherwise there’s a bit of feedback from both Gavin and Graham, and that’s it for this nearly 40-minute episode.

March 2, 2013

Podcast #67: Russian Meteor Conspiracies


I first said I wouldn’t do it, then I did it: Chelyabinsk meteor conspiracies! The episode is just a tad longer than the last one at a bit under 25 minutes.

The topics covered, besides setting the scene and what’s really known about the meteor, I talk about the coincidence of time; the coincidence of location; the conspiracies of missiles, UFOs, and Planet X; whether it was sent by some p—ed off deity; and the unfortunate scam that’s cropped up.

Besides all that, there’s a bit of feedback that lends itself to one of the (yes, of the two!!) puzzlers. And a quick announcement or two (depending on how you count ’em) rounds out the episode. One of those announcements is that I will only be doing two episodes this month. Somehow I managed to put out 4 last month despite writing 3 grants, but this month is just insane along with 8 days of travel in the latter half. Sorry.

Remember that Expat will be on the next episode talking about some of the conspiracies related to politics, secrets, and engineering of Richard C. Hoagland. If you have something you really want me to ask him, feel free to send it in (or comment below).

January 16, 2013

Podcast Episode 61: Special Pleading with Large Impacts


A complaint I’ve heard is that the invoking of giant asteroid impacts to explain some odd solar system features (Venus upside-down, Uranus on its side, etc.) is just special pleading and as crazy if not more so than the pseudoscience ideas, like Velikovsky. While I obviously have my own opinion about Velikovsky in particular, I wanted to take an episode to talk about why giant impacts are used to explain some things, and whether we have a real reason to do so or if it’s just our own way of making stuff up.

There isn’t a new puzzler, though the one from last episode – send in your favorite planetary pareidolia – is still going on.

January 10, 2013

No, Asteroid 99942 Apophis Will NOT Hit Earth in 2036

Filed under: asteroids,astronomy — Stuart Robbins @ 12:40 pm
Tags: , , , , ,

New radar observations during Apophis’ close approach to Earth over the last few days have narrowed down the uncertainty in its orbit enough to know that it will NOT hit Earth in 2036, according to an article published in Sky and Telescope (I’m still trying to track down a more primary source).

This is despite still not knowing several things about it (like its shape), but the uncertainties on its orbit are now so small that the combination of all the other unknowns are too small to put it on a collision course with Earth in 2036.

That’s all the info I have on this for now. Doesn’t mean it may not hit in the future, and it doesn’t meant that something else won’t hit in the future. When looking for things in space to kill us, asteroids are by far the most likely because we know it WILL happen, it’s just a matter of when and how big.

Edited to Add: And here’s more of an official story, this one from NASA’s Asteroid & Comet Watch.

January 9, 2013

How Astronomers Are, According to Popular Press, Constantly Discovering the Same Thing


Introduction

This post was prompted by a bit of discussion both at work and on my blog lately.

Regarding the blog, the question has come up of when people have known different things, and laypeople going to popular press to determine when stuff has been discovered.

Regarding work, an e-mail was sent out yesterday with one of the senior scientists wondering what the big deal was with a press release claiming to have discovered something new, but he pointed out a paper from 1984 that said the same thing.

So I thought I’d talk a bit about why the media (and official science organizations’ press offices) keep announcing a “new discovery” when it’s, in fact, a very old discovery.

Example from Yesterday: “NASA, ESA Telescopes Find Evidence for Asteroid Belt Around Vega”

On January 8, 2013, NASA released a press statement #13-006, “NASA, ESA Telescopes Find Evidence for Asteroid Belt Around Vega.”

If you read it, the very first part of the very first sentence states: “Astronomers have discovered what appears to be a large asteroid belt around the star Vega.” If you read further, it’s all about implications, comparing it with other recent discoveries, and what questions future studies hope to answer.

It all seems as though this is a very new and interesting finding, and as a press release (and from NASA, no less), it was picked up by many news outlets (looks like at least 35 from a Google News search as of posting this).

I’m not trying to minimize these researchers’ work, and if you want to read their paper, it’s posted here.

But, turn the clock back 30 years. In June 1984, in the journal Science – one of the preeminent journals in the world – there was a paper published by Paul R. Weissman with the title, “The Vega Particulate Shell: Comets or Asteroids?”

If you read the abstract, it states: “The [IRAS] science team has discovered a shell of particulate material around the star Vega. … The Vega shell is probably a ring of cometary bodies … . … A possible hot inner shell around Vega may be an asteroid-like belt of material a few astronomical units [the distance between Earth and the Sun] from the star.”

We didn’t have the internet back then, but based on a Google News archive, at least one newspaper, the Boston Globe, mentioned it in October 1984.

It is true that these are not exactly the same thing. It’s true that the new data are much better 30 years later. But the basic idea is the same: We knew 30 years ago that Vega had a debris disk around it of at least cometary and maybe asteroidal material as well.

Ergo, the press release title is misleading. And, anyone who does a news search who’s looking for when particular things may have been discovered – or at least probably discovered – in science will be mislead … in this case, by 30 years.

Why?

Listening to The Skeptics’ Guide to the Universe podcast, I have definitely become somewhat jaded with news reporting. Having had my own press release come out about some of my work last year, I have had my own issues (a simple comma missing in the final copy – removed after I had approved it – completely changed the meaning to make it seem like I was talking about ice volcanoes on Mars).

Given my experience, my best guess is that it’s the press officers’ job to get as much publicity for their subject as possible. And we’re lucky if we get to see the final version before it gets sent out. A press release with the headline, “NASA, ESA Telescopes Re-Find [or Confirm] Stuff Found 30 Years Ago” is not going to stoke public interest.

For a topic closer to my own research, it’s the same case with water on Mars. We had darn good evidence back in the late 1960s and ’70s after the first spacecraft images were returned that there had been large amounts of surface water on Mars in its past. But, every few months it seems, a press release comes out stating that a new study has “discovered” water on Mars (or in Mars, or recently on or in Mars, etc.). It’s become something of a running gag during weekly science discussions.

Final Thoughts

To those who did the original (or previous additional “new discovery”), it’s frustrating they don’t get credit. It’s also somewhat insulting. The new Vega paper in this case doesn’t even cite Weissman’s work.

To be fair, this isn’t a huge issue. It’s not media misreporting something major, it’s just a short memory span. But, to those of us who do research in the field or closely related fields, it’s another example of marketing spin taking precedence over honesty. And for laypeople trying to figure out when something was known or discovered, it makes it seems as though everything was much more recently known than it actually was.

January 7, 2013

No, Asteroid 99942 Apophis Won’t Kill Us This Week


Introduction

Unfortunately, the UK’s The Guardian has a misleading title in an article that came out today (January 7, 2013): “Apophis – a ‘potentially hazardous’ asteroid – flies by Earth on Wednesday.”

Now, technically, the headline is correct. For awhile, asteroid 99942 Apophis (or just “Apophis” for short) was potentially dangerous with as much as a 1 in 37 chance as calculated in December 2004 of striking Earth in 2029. Then, the worry was that in 2029 during a close approach, it might pass through a very narrow region in 3D space that would alter its orbit so it would come back in April 2036 and strike Earth.

Apophis’ Orbit

To be clear, from hundreds (if not thousands) of observations at this point, the chance of it striking Earth in 2029 is as close to 0 as you can get, and the chances of it striking in 2036 is about 1 in 250,000. Yes, 2029 will be a very close approach, with estimates being it passing by at only 5.6 times the radius of Earth. But that’s not a hit.

So what’s all this then about 2013?

It’s just a close approach. It’s the closest approach in awhile and it will let us refine its orbit even more.

Why do we need lots of observations over a very long time to get a better orbit? It’s like watching a hot air balloon in the sky: If you observe it for 3 seconds, you can get a very rough idea of how fast it’s going and where it’s headed. But if you watch it for 3 minutes, you’ll have a much better idea. And if you watch it for 3 hours, even better. It’s the same idea with asteroids, or really anything else.

That’s why this Wednesday, January 9, with its closest approach in awhile and for awhile, is important. The closer it is, the better we can pin-point its position and so the more accurate orbit we can derive in the future. We can also get a better estimate of its size. But, this approach is perfectly safe – Apophis’ closest approach this year will take it about 37-38 times farther than the moon.

Final Thoughts

I wasn’t even going to comment on this, but I’ve already seen people asking on various forums based on The Guardian‘s headline. So, there it is. Yes, technically Apophis is “potentially dangerous” because, based on our current orbit estimates, there’s a 0.0004% chance of it striking Earth in 2036. But no, the world is not going to end in 2 days after just “narrowly” surviving the “Mayan apocalypse.”

I’m hoping that the author of the article, Stuart Clark, didn’t select it. He’s written popular astronomy books and various other things, so he should know better unless he was trying to drum up page views. I’m guessing it was some editor.

April 8, 2012

Podcast Episode 30: Was the Asteroid Belt a Planet? Part 2 (Exploding Planets!)


The follow-up to last episode, this one deals with Tom Van Flandern’s idea that Mars was a moon of an exploded planet that formed the asteroid belt 65 million years ago. So, last episode was basic science, this one gets back to some of those wacky and wonky ideas. Oh yeah … and lots of Coast to Coast clips!

I also spend around 10 minutes discussing feedback from the last episode.

March 31, 2012

Podcast #29: Was the Asteroid Belt a Planet? Part 1


In this episode that is one second shy of 30 minutes, I talk about some of the historical reasons why some people may think the asteroid belt was at one time a planet, but then I go into four ways to show that it could not have been a planet. Next episode (“Part 2”) will get more on the wacko-conspiracy/crazy/pseudoscience exploding planet ideas.

September 24, 2011

Follow-Up on the Dino-Killing Asteroid


Introduction

Last night, after making my post “What’s Going on with the Dinosaur-Killing Asteroid?” I contacted the lead author from the original 2007 paper, Bill Bottke (in the interest of full disclosure, I actually collaborate with him and see him about once a week, including yesterday morning).

I asked Bill if he would be willing to glance over the short post and let me know if I got any of the science outrageously wrong. His reply was a bit more than I had expected of a simple “yes” or “no,” where he instead wrote a more elaborate explanation of what was going on. I asked if I could post his response to my blog as an addendum and instead, he sent a more detailed reply for me to post. Since it was somewhat lengthier than the original post, I figured I’d just make a separate one. What follows is Dr. Bottke’s reply, slightly edited for grammar/spelling as he requested.

Note: You should read my original post before reading Dr. Bottke’s response.

Bottke’s Reaction

First of all, this is science, and not every idea is going to work. One has to do the best one can with the available data, and some models do not survive first contact with new observations.

With that said, let me try to realistically assess where we are and where we are not.

From the dynamical end of things, having a smaller parent body and smaller family members means things can get out of the main belt faster than before. If anything, this moves the impact closer to the peak of the impact spike distribution, which is good for our 2007 model. Moreover, many potential impactors can now get out by being injected directly into the “escape hatch” right on top of the family. We did not model direct injection in detail in 2007 because the K/T hit appeared to be made in the tail of the Baptistina shower — those results would not impact our work. Now that things have changed, we can examine this more closely.

Overall, I find it highly suspicious that K/T occurred in the middle of the Baptistina asteroid shower. Asteroid showers are very rare in solar system history, though coincidences do happen in nature. This makes me think the new results could potentially strengthen our story, not weaken it.

A smaller asteroid means there are fewer large projectiles in the Baptsitina population. This hurts our original model. Interestingly, though, new estimates of Ir (iridium) and Os (osmium) associated with K/T that came out after our paper suggest the impactor may have had a diameter 4-6 km, not 10 km, so this may all be a wash. Impact energy is strongly a function of velocity, and impact velocities on Earth can be very high for asteroids, so there is not necessarily a contradiction here. For those that want to know more, see recent papers by Frank Kyte and Paquay et al. (2008) (“Determining Chondritic Impactor Size from the Marine Osmium Isotope Record” in Science).

The main hit to the 2007 story from the recent WISE work is composition. If Baptistina and its family members turn out to be a different asteroid composition than we suggested in our 2007 paper, we cannot link the family to the limited compositional information we have on the K/T impactor. From Cr (chromium) studies of K/T terrains on Earth, it looks like the impactor was a particular kind of carbonaceous chondrite. A high albedo (reflectivity) for Baptistina could suggest it is not actually this composition. Preliminary spectra for Baptistina family members may also work against it being a carbonaceous chondrite, though most of the family has not been examined from a spectral standpoint. Observers have mainly looked at asteroids near Baptistina, not “in it” as defined by our paper, and interlopers in this part of the main belt are a major pain to deal with. What observers need to do is look at the prominent “clouds” of objects observed for the family, where interlopers are less of an issue. This should be dealt with in the near future.

Note that if Baptistina family members turn out to have a radically different composition than carbonaceous chondrite, it would imply we were strongly misled by the Sloan Digital Sky Survey colors for Baptistina. Nearly 300 objects have been examined, and they have been classified as C/X-types of asteroids, which link to most objects as carbonaceous chondrite-like objects (see Parker et al., 2008).

There is also the surprising and unusual possibility that some asteroids that look like carbonaceous chondrites may have higher albedos that we expect. For example, interesting work on (21) Lutetia, which was recently visited by the Rosetta spacecraft, has a high albedo and a composition that many say looks like a carbonaceous chondrite. For those that know and love asteroid taxonomy, K-types asteroids look like they may be able to produce many kinds of carbonaceous chondrites, yet they are spectrally similar in many ways to those asteroids that may produce ordinary chondrites.

Note that even if composition is knocked away, one could question whether Cr is diagnostic, or whether different parts of the asteroid could have different Cr signatures. However, this strikes me as a desperation ploy, and I will do no more than mention it until new information on Cr comes to the fore.

Final Thoughts

With that response from Bill – more technical than I normally have in my blog but I think important for those who are interested – I’ll close out by reminding readers of what he stated at the beginning and what I have stated many times on this blog: This is how science works. We make observations, gather data, create models, make predictions, and in light of the evidence revise our models or make new ones. Contrast that with the way many creationists, conspiracy theorists, UFOlogists, astrologers, etc. work.

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