Sunjammer

In case you were wondering, the title of this post is the name of a short story by Arthur C Clarke in which solar sail-powered spaceships race each other around the moon.

Ok, that’s cool, but why do I bring this up? Because the Planetary Society is going to be launching a solar sail spacecraft in about a year! An anonymous donor contributed enough money to jump-start the program. The Society had a previous solar sail spacecraft attempt, but the Russian rocket it rode to space malfunctioned and instead of sailing through space, Cosmos 1 ended up in the Bering sea.

Solar sails are a very cool idea, but they have never been tested before, even by NASA. They work because sunlight is capable of transferring momentum, particularly to shiny surfaces, so a solar sail spacecraft just extends it giant silvered wings and hitches a ride on sunlight. It’s a “free” form of propulsion that could be used to accelerate probes without the need to launch heavy rockets and fuel tanks.

Needless to say, people at the Planetary Society are pretty excited about this opportunity to make space exploration history. To read more about the mission, check out this New York Times science article.

(PS – did you remember to vote for my article about MSL over at scientificblogging.com? You can vote daily until the 23rd!)

Big Picture HiRISE Gallery!

Speaking of Mars art, the Big Picture blog (which all of you should be following by now) has a feature on images of Mars taken by HiRISE. Head on over and take a look. Mars is a really pretty and often bizarre-looking place.

[PS - Have you voted today?]

Mars Art: Mind-blowing Swiss Cheese

First of all, a reminder to go vote on my article about MSL, which is a finalist in the scientificblogging.com science writing competition.

Ok, done? Good. I wanted you to do that before I showed you this image because it may very well break your brain. This is a HiRISE image of the so-called “swiss cheese” terrain at the south pole of mars. The terrain is formed by the sublimation of CO2 ice, which forms weird rounded pits. Yes, the round things in this picture are pits.The smooth parts are mesas and the illumination is from the lower right. Pictures like this always make my brain hurt because for some reason I want to see the round depressions as bulges! And if you think this is bad, try watching a scientific presentation with dozens of pictures like this, with varying orientations and illumination angles. I rarely get anything out of Mars south pole talks because my brain is so busy struggling to see the images properly.

Believe it or not, illumination is from the lower right in this image. Click the image to go to the HiRISE page and check out the full sized versions.

LCROSS preliminary results

Hey remember when we bombed the moon? Here’s an interesting article about some preliminary results from LCROSS. I was especially surprised when they said that there may be mercury at the impact site. They say they’re seeing spectral lines that could be produced by iron, magnesium or mercury, but then the article goes on as if mercury is the likeliest candidate! I’m skeptical. Fe and Mg are common in lunar rocks. Mercury: not so much. Oh well, it’s an interesting update anyway, and it sounds like the real juicy results are still in the works.

PS – Have you voted today for my MSL: Mars Action Hero article over at the scientificblogging.com science writing competition? Remember, you can vote daily!

How Habitable is the Earth?

Charlie Stross has an interesting post on his blog that asks the question “How habitable is the Earth?” He goes on to conclude, through a great discussion of the evolution of our planet, that the fraction of time that the earth has been habitable to humans is a tiny sliver of the time the Earth has been around, and that furthermore, much of the earth is not habitable for humans because it is water or ice or mountains. If much of our planet, even now, is not habitable, he argues, what hope is there of finding other habitable worlds out there in space?

It’s an interesting discussion, but I find it somewhat misleading. It makes the rather large assumption that for a world to be considered habitable, a human would have to be able to survive for 24 hours, naked, on the surface. Ok, that’s one definition of habitable. But if you are postulating that these humans are capable of interstellar travel, it seems like you might make allowances for the use of clothing and the ability to build shelter. After all, we’ve known about those ones for a while. You could go even further and suggest that these humans might be able to alter the air they breathe, either through individual gas masks, or on a planetary scale. We used CO2 scrubbers on the Apollo missions to make the air breathable, maybe that would work on a planet with otherwise unbreathable air?

I think he’s fundamentally right in terms of human habitability: the likelihood of a planet being perfectly attuned to humans is extremely low. We evolved to live on Earth and nowhere else. We are going to have to make some adjustments to ourselves or our environment to live anywhere else.

The problem is that he then extrapolates and suggests that this might explain the Fermi paradox (aka. if there are so many stars and planets out there, why haven’t we heard from any little green men?). But that is completely off-base! He is essentially saying that, because humans evolved to live on Earth and nowhere else, it is unlikely for anything else to be living out there because there are likely few earth-like places. That does not follow. There could be aliens out there that are completely happy on their planets that would be instantly lethal to us. And it’s entirely possible that if they set foot on Earth they would find it a very hostile and uninhabitable environment (and not just because of the terrified earthlings).

Anyway, it’s an interesting article. Go take a look.

And speaking of interesting articles, have you gone and voted for my MSL: Mars Action Hero article over at scientificblogging? I’m one of the finalists for their science writing competition, so take a look and vote for me if you like it. To see the other entries, click here. Feel free to vote for as many as you like, and remember you can vote daily until the 23rd!

 

Voting is fixed!

There were some issues with the voting widget on the University Science Writing competition, but they have been resolved, and it turns out it was counting the votes all along! So go vote for my post if you haven’t done so yet today! Don’t worry if you don’t see a number in the grey voting widget box. They decided to hide the number of votes from everyone except the authors.

Ans while you’re there, go ahead and check out and vote for other finalists too. There are some great other posts!

Edit: Can anyone else see the voting widget on my post? I just edited the voting instructions in the text to reflect the fact that they got rid of the visible number of votes, and when I saved, the widget disappeared.

Vote Early and Often!

Remember when I mentioned a few weeks ago that I submitted a blog post about MSL as an action-adventure hero  to ScientificBlogging’s  science writing competition? Well they have announced the finalists and I’m one of them! From now until November 22, all the finalist posts are open for voting. You can vote for as many entries as you want each day, every day! So that means that you can vote for my post 22 times! To vote, go to my post and click on the little gray counter to the right of the title.

The winner of the competition gets $2500 and a 3 month writing internship at ScientificBlogging.com, and the runners up get $1000 and $500. So please, vote early and vote often! Thanks!

 

NaNoWriMo 2009

Well, it’s that time of year again. Against my better judgement, I have decided to participate in National Novel Writing Month (NaNoWriMo) again this year. For those unfamiliar with NaNo, the idea is to write a >50,000 word novel in the month of November. It’s a great way to get over the inner editor and just write, and I’ve been putzing around with this year’s story idea since earlier this year. It’s time to get it out of my head and onto the page.

What does that mean for this blog? Well, updates may be less frequent. But if I recall, last year I actually updated more often, possibly because I was already in the writing mindset. You can also follow me on Twitter, where I’ll be sharing cool links and tweeting about life and science and writing.

 

Big Picture: Ares 1-X Launch

The Big Picture has a great series of photos of the Ares 1-X launch, including some really fascinating shots of all the preparation that went into it. Check it out!

New Photos of Stuff on Other Worlds

I always make the mistake when on vacation of taking too many pictures of scenery and not enough pictures of people. Years down the road, the most interesting photos are not landscapes, but the ones that we can look at and say “I remember when we did that!”. And that’s why I think it’s great that we now have cameras around the Moon and Mars that can do the same. LROC at the moon has been able to take some spectacular photos of the Apollo landing sites, including a new one shown below. HiRISE at Mars has been able to take photos of the Mars rovers, Viking landers, and more recently the Phoenix lander.

Phoenix went silent as northern Martian winter crept in, covering it with CO2 frost, but the latest HiRISE image, taken in the spring, shows an ice-free Phoenix! It probably won’t wake up again, but it’s good to see our lander again. The spring images are somewhat grainy because the sun had just peeked above the horizon and light levels were very low. Emily Lakdawalla has a post with more information about this and other HiRISE images of Phoenix.

Credit: NASA / JPL / UA / animation by Emily Lakdawalla

If it’s fun to see our robots again, it’s even cooler to see evidence of humans landing on the moon. Now that LRO is in its final orbit around the moon, it is returning some really excellent photos of the Apollo landing sites, including this new one of the Apollo 17 site. You can even see the flag! For more information and closer views, check out the LROC site.

This high-resolution view of the Apollo 17 landing site shows details as small as the flag! Click to go to the LROC site for higher-resolution versions.