asterroc: (Astro - H-alpha)
1) They've cried wolf enough times at this point that I'm always skeptical about every new announcement.

2) This is yet more indirect evidence - they've found visual evidence of changing patterns that could look like streams, and in the same areas spectra give the chemical "fingerprints" of assorted salts (not table salt, NaCl, but chemically similar) which as far as we know can only form in water.

To me, if the evidence is indirect, we will need a lot more of it than if we actually saw liquid H2O flowing and used spectra to confirm it was water. Right now we have circumstantial evidence of things that look like stream beds (but could be caused by other liquid solvents, or a remote chance they're caused by wind), and we a number of chemicals which as far as we know can only form in water (not only these salts, but also the hematite blueberries from a few years back). However the hypothesis "this can only form in water" is one of those things we can never actually prove true, just eliminate more and more untrue possibilities.

So to me as a watcher of all this, it's just a waiting game. If there really is liquid water, then little pieces of evidence like this (and the hematite blueberries) will continue to build up until at some point the molehill has become a mountain and it'll be generally accepted by all planetary astronomers (and then all astronomers, and then the world) that yes, there's liquid water on Mars.

3) Water is a key building block for life, so the next question is "is there life on Mars?" Assuming this liquid water exists, it is transient - it's seasonal, appearing only in local summer. If it's transient liquid water, I will need to see some pretty solid evidence to believe that there is current single-cellular life. If it's persistent liquid water I will switch over entirely and I will assume that there's single-cellular life until proven otherwise. Even if it didn't evolve on Mars, we've sent missions there and it's impossible to sterilize everything completely, plus bits of Earth have been knocked off from impacts and landed on Mars so it might've been seeded with Earth life millennia ago. If it's possible to sustain some form of life on Mars, I guarantee you that it's there.

Originally posted on Dreamwidth. comment count unavailable comments there. Comment here or there.
I have a theory about blood moons. Would you be so kind as to fill out this poll about tonight's? Put anything else you want to say (or share pics) in the comments. :)

[Poll #1964650]


Feb. 10th, 2014 10:09 am
asterroc: (Astro - H-alpha)
Like any good researcher, when I noticed students responding a certain way to a free response question, I tried to tabulate what they all said, and turned it into multiple choice. Basically, the students were trying to describe why we don't have solar and lunar eclipses every month. The drawings below are based on the word descriptions from the students. And I wanna know what you think: which picture is the main reason why we don't have solar and lunar eclipses every month?

Descriptions in words:
A) "The Moon is in a different plane."
B) "The Moon's axis is tilted."
c) "The Moon goes above and below."
D) "The Moon's orbit isn't a perfect circle."
E) "The Moon's orbit is tilted."

2014-02-10 09.40.21

[Poll #1956047]
asterroc: (Astro - H-alpha)
A FB comment just reminded me my head was totally blown yesterday in cosmology.

When I teach Astro 101 I tell my students that we know about the Big Bang because we see that things are moving apart from each other right now, so this means they once had to be closer together in the past. Kinda like if we're watching a fireworks show, and we look away for a moment and turn back to see a firework after it's already exploded. We see the glowing bits moving apart from each other, and we know that perviously they all came from a big explosion. That's just like the Big Bang.

Turns out I'm wrong.

The rest of this post is based around two graphs, one which I already knew about and one which blew my mind. The text will extensively explain these graphs, hopefully sufficiently well for non-typically visioned people as well. Continue on if you want to learn some cosmo.

Here's a graph I already knew about, with an explanation. )

Here's the second graph which blew my mind, with an explanation. )

So yeah, that was my big HOLY SHIT moment yesterday, realizing what that "NO Big Bang" meant.

Hope you learned a bit of cosmo there. :)

Originally posted on Dreamwidth. comment count unavailable comments there. Comment here or there.
asterroc: (Astro - H-alpha)
A few questions about terminology in astronomy... For any of the "Something else"s, I encourage you to comment. Or just in general, feel free to comment, though I'd appreciate it if you filled out the survey before you read the comments.

NOTE: third question didn't come out right, it's supposed to read "Are either the words 'size' or 'bigger' ambiguous to you?" If you care to add this in the comments, I'd love to know. :)

[Poll #1929305]


Jun. 11th, 2013 10:49 pm
asterroc: (Astro - 2MASS)
My students this semester found this question more challenging than they usually do. It's small number statistics and all, but I'm curious what y'all think. Please answer before viewing other people's answers, and if you care to explain your reasoning in the comments, I'd love to see.

[Poll #1918673]
Okay, here's the skinny on Kepler-62e and f, the latest potential "Earth-like" planets. I'm numbering my points in case you want to refer to them elsewhere.

Enough detail for a science fan, more detail than most news sources will have, not enough detail for an astronomer. )

So that's my summary. If you want to read other articles, here's the Nature layperson's article which does a good job of not overhyping things. And here's the peer-reviewed journal article in Science (really prestigious!, though my dept has a running gag that 50% of Science and Nature articles turn out to be wrong). I believe the Science article is behind a paywall if you're not at a university, so if you want to read it and can't access it, let me know and I can email it to you.

Originally posted on Dreamwidth. comment count unavailable comments there. Comment here or there.
A quick survey for those following along at home. Please complete the survey before checking others' responses or comments below.

[Poll #1817087]
Just watched the last Space Shuttle launch, Atlantis, on TV.

In my entire life I have now watched a grand total of three Space Shuttle launches (all on TV):
* Challenger, 1986
* Discovery, 2005
* Atlantis, 2011

According to my recollection, I was in third grade when my teacher decided that we would all crowd around the little 10" classroom TV to watch the first teacher go into space. We all know how that ended. I remember the entire classroom being silent for a long time before my teacher said anything.

For nearly two decades after that I was mostly against human spaceflight. It cost too much money, there was too little return on investment, and it was too risky, said the emotional side of me. The intellectual side said that others found it inspiring so we should continue human spaceflight to drive funding of real astronomy, and I also thought it was important to someday colonize other places than Earth so we must start that somewhere.

2005 was Discovery's "Return to Flight" mission, after the 2003 Columbia disaster. That summer I happened to be teaching astronomy at a nerd camp, so my TA on his own initiative arranged to have the class crowd around a TV screen. He and I stood in the back of the classroom chanting to each other, "I hope we don't traumatize them, I hope we don't traumatize them." Thankfully, we did not.

In 2008 the first teacher to actually go into space, Barbara Morgan, originally a backup for Christa McAuliffe and actually flew on Endeavour in 2007, addressed the National Education Association in Washington DC. I remember little of her speech, other than that it was inspiring.

Today I watched Atlantis launch on TV, the last ever Space Shuttle mission. My heart was in my throat and tears in my eyes, hoping that this would not be another disaster. Atlantis did launch successfully at 11:29am (EST). More than an hour later now, I'm not sure if it's already in orbit, or if it's still climbing.
Bad Astronomy (Phil Plait)'s post on the subject

House Committee on Appropriations post on the subject

Write your own letter to Congress (site via the National Education Association, but you'll be writing your own content and can opt out of sending a copy to the NEA or getting on their email lists)

Model letter to congress on the subject )
Am I the only one who is severely bothered by the seasons in "A Game of Thrones"? A big premise of the "A Song of Ice and Fire" series is that seasons last multiple years. But, at least in the first book, there isn't any explanation of this given, not even a supernatural/fantasy one.

Cut for people who don't care about why this bothers me. )

In the end, I think I have to conclude that Martin doesn't know jack about astronomy, even what they teach you about the seasons in elementary school, and just move on and try my best to stop gritting my teeth every time he refers to multi-year seasons.

And I'll leave you with this.

Axial Tilt is the Reason for the Season
NASA's big press release today was that a new form of DNA was discovered in a type of bacteria living in Mono Lake, California. DNA usually requires phosphorus to hold together the different "rungs" of the "ladder". On the periodic table of the elements, phosphorus falls directly above arsenic, meaning they have the same number of electrons in their outer shells, and therefore act similarly in forming molecules. This is the very reason that arsenic is well-known as a poison: it is easily incorporated into human (or animal, or plant) chemistry, it replaces the phosphorus, but it does a crappier job than phosphorus and even though it can form similar molecules they easily fall apart.

Apparently this bacterium has not only overcome that - there are many bacteria that can live in an arsenic-rich environment - but it even uses that fact. This bacterium can apparently switch between using phosphorus, and using arsenic, depending upon which is available in its environment.

NASA press release

A very slightly more technical article, including a description of tests used to determine that the arsenic is actually incorporated into the DNA.

And a couple blog posts, one from a science writer Ed Yong, one from astronomer-turned-science-writer Phil Plait.


Feb. 20th, 2010 11:00 am
In case you haven't seen it, I've compiled a list of time wasters and flash games for anyone who wants to waste some time. Just added GalaxyZoo to the section of Science things.
asterroc: (Astro - H-alpha)
I have an invite for a Google Voice number, which would allow me to link my personal (cell) and work numbers together, and I can select which phone rings when specific people call me, or have neither ring at all. I would give this number out to people who know me personally, professionally, or even through teh intartubes only. I've got a few ideas and I'm wondering what others think of them, or if you have other suggestions for me that aren't already taken.

[Poll #1444709]
40 years ago today the first man walked on the Moon.

Tomorrow I'm meeting the astronauts who serviced the Hubble Space Telescope for the last time on the STS-125 mission. [ profile] jmgold42 suggested as a question for them "Do you think we should go back to the Moon?" and I just may ask it (though I expect someone else will ask it). [ profile] blue102 suggested a question about how their perspective of Earth has changed, and how the Earth-bound of us can achieve that. I'm also considering "Do you think NASA should focus its energy and funding on manned or unmanned missions?" You can follow along with the NASA Tweetup event at the Twitter hashtag #NASATweetup.

If you could ask the STS-125 astronauts any question, what would it be?
asterroc: (Smoothie)
I've got a sabbatical coming up Fall 2010. I'm seriously considering spending 6 months in Australia. For professional reasons, really! I want to see the night sky south of the equator, and I could do astrophotography. (On the personal side I really want to live in a place where cockatoos will come to my birdfeeder.)

So, I know very little about Australia except what I've just said. Help me find out (a) where I should do this, (b) how much it will cost, and (c) whether I need a visa! This's currently a pipe dream, but every dream starts somewhere.

The World

May. 10th, 2009 11:06 pm
I'm trying to understand something. Please answer the below questions to the best of your ability.

[Poll #1397877]

What I'm trying to understand - read this AFTER submitting the poll )
I was in second or third grade when my teacher decided to have us all crowd around the TV to watch the first teacher going into space. Of course you all know that it was the Challenger, and our childish excitement turned into confusion. I don't remember my reaction at all, nor what my teacher said/did - I wish I did recall in case as a teacher I ever have to face this situation myself. In 2005 I watched Discovery's return-to-flight mission with bated breath, having just asked my students to crowd around the TV to watch, hoping Challenger and Columbia wouldn't repeat themselves in front of my students. I tell people the Challenger incident is why I was never interested in becoming an astronaut, but I'm not sure if this really triggered it or if the interest was never actually there.

Last summer I heard a speech by Barbara Morgan, the actual first teacher in space, on Endeavour in August 2007. She had been Christa McAuliffe's backup in 1986, and she didn't fly until 21 years later. Morgan's speech about the importance of science and math in children's education, and how Christa would have wanted the program to go on no matter what, was quite moving. I am not a fan of manned missions for science purposes, but for inspirational purposes they are absolutely 100% necessary.
In case anyone's interested, I thought I'd post some answers to the quiz questions I posted the other day asking people for help in timing online quizzes.

Regarding the timing issue, everyone reported that it took them a very short time to type their answers - admittedly it's a self-selected group (I doubt slow typers would enjoy blogging all that much, and people who hate science probably wouldn't be answering these questions for me), but still it gives me a starting point. My plan with my class is to (a) ask students during the first week about their typing skills, (b) unless any of their answers worry me, I'll give the same amount of time for the first quiz as I would give in a face-to-face class, (c) I'll look at the statistics of how long it took them to complete the quiz and adjust subsequent quizzes accordingly.

So, for the answers )

Once again, thanks for the help!




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