Last-minute Astro and Space Gifts

Well, the annual gift-a-thon is in countdown to the final hours now and there are probably some of you still figuring out what to get for that certain someone (or yourself!).  I’ve mentioned some cool ideas over here and here and here (so check out those links, too!), but I always have more to talk about.

My perennially favorite calendar arrived (thanks to the publisher!) and it’s going to be hanging on my wall any day now. It’s called The Year in Space 2015 Calendar, and its published in cooperation with the Planetary Society (one of my favorite space advocacy organizations). It has a year’s worth of gorgeous images, space facts, and other interesting information about the sky and our exploration of the cosmos.  You can get it at The Year in Space Web page and I highly recommend it. One of the nicest and loveliest space calendars out there!  It’s a great gift.

One of the more offbeat gifts I’ve seen (and I ordered this for myself so I can’t wait to see it) are the constellation earrings over at Thinkgeek.com. The constellation Orion is one of my favorites, so they’re entirely appropriate! Thinkgeek also has a lot of other nerdly and spacey gifts, so browse around while you’re over there. (No, I don’t get paid by Thinkgeek — I’m just a satisfied customer of many years’ standing.)

A friend alerted me to the many fantastic astronomy and space themed objects at Etsy. Among them are spacey cufflinks, prints, clothing, and much more. This link takes you to a search I did at Etsy, using the term “astronomy gift ideas”.  There are some pretty cool things there, made mostly by artists selling their own work. Worth a look!

While you’re at it, think about giving gift memberships to the space-happy folk on your list.  The Planetary Society is a good place to show your support for space travel and exploration. If you or your giftee live in or get to Los Angeles quite often, please consider a gift membership to Griffith Observatory’s support group called Friends of the Observatory. They do an outstanding job of promoting and supporting this fantastic institution and your dollars help support a wide variety of programming efforts (including school visits).  If you’re outside of the LA area,  check out gift memberships and certificates for and from your local planetarium and science center gift shop.  Also consider a gift from Astronomers Without Borders. This organization brings astronomy to people around the world, regardless of where they live.  Another good astronomy educati0n resource that offers memberships is the Astronomical Society of the Pacific. The group has a large international presence in astronomy education and outreach, with a fantastic online presence (and gift shop!).

Of course, the best gift of all is sharing your own knowledge of the sky with others. It doesn’t cost you a cent, and allows you to teach others about the science of astronomy. So, maybe a “selfie” gift certificate promising some stargazing time with your best friends and family will be just the ticket. You can even dress it up by printing it out on one of the Hubble Space Telescope’s free, downloadable holiday cards!

Whatever you do, have a wonderful holiday season!

The Answer May Involve Several Sources

In my last posting, I talked about the news that Comet 67P/Churyumov-Gerasimenko carries water that is isotopically different from Earth water, and the implication that this has for cometary water delivery to early Earth’s oceans. In other words, based on the Rosetta mission’s study of that comet, it’s not likely that the type of comets that 67P came from could have delivered the water that Earth needed. This conclusion (among others) has led planetary scientists and geologists to look at other sources for water. Water-rich asteroids are one possible source, and they’re being looked at in greater detail. Generally speaking, it seems an interesting line of research to follow up on, since Earth accreted from planetesimals in the early solar nebula, and bits and pieces of those early planet “seeds” still exist in the Asteroid Belt and inner solar system.

However, there’s yet another proposition for Earth’s water is catching some attention. This week researchers at Ohio State University announced results from a study they’ve done that suggests early Earth made some of its own water through known geological processes. So, essentially, our planet formed from rocks that had the “stuff” of water (hydrogen and oxygen) bound up in them. When subjected to the heating induced by plate tectonics, the rocks can be made to release water, and that may be what has fed (and continues to nourish) our oceans.

This doesn’t discount the idea that comets also delivered water to the planet, but the evidence this week of wildly differing D/H ratios in some comets (particularly Comet 67P/Churyumov-Gerasimenko) certainly pokes a hole in the idea that ALL the water on our planet came from the infall of comets over time. Yes, there are comets that have D/H ratios closer to Earth’s D/H in its water, but not all comets do. And, if the D/H ratios don’t match, then you have to look at other sources of water. That’s where the Ohio State study comes in. You can read more about it here.

Continue reading Where DID Earth’s Water Come From? →