Yearly Archives: 2012

cassini, cassini mission, enceladus, saturn, titan

A Mini Nile on Titan

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Cassini’s Latest Find on Titan

A river and delta system on the surface of Saturn’s largest moon, Titan. Courtesy NASA/ESA.

The hits just keep on coming for the Cassini Solstice mission (a joint effort between NASA and the European Space Agency). This time it has sent back a radar image of what looks like a miniature version of Earth’s Nile River delta. It stretches across more than 400 kilometers (about 250 miles). Some kind of liquid is flowing through it, and scientists suspect that it is following along the boundary of a fault (a crack) in the surface. The river empties out into a Titan sea.

Titan is an interesting place. It’s got liquid flowing across its frigid surface, as well as lakes and small seas. Planetary scientists think the liquid that cycles from surface to the atmosphere and back again contains hydrocarbons such as ethane and methane. That’s not all that weird, really. Early Earth may have had a similar environment before things settled out some 4 billion years ago. What this image, and the many other images and observations about Titan tell us is that this is a lively world — it has activity on its surface, and there’s clearly something going on inside this moon that keeps things bubbling along. It experiences seasons, something that astronomers had not expected to find when they sent the mission.

The Cassini Solstice Mission is one of the great success stories in planetary exploration. It was launched as Cassini-Huygens in 1997 and has been tracing an orbital mission through the Saturn system ever since its arrival in 2004. It finished its initial four-year-long mission in 2008 and has been extended twice to continue exploring Saturn, its moons, and rings. It dropped the Huygens lander to the surface of Titan and that gave us our first in situ look at this once-mysterious moon.

The current mission goes through September 2017 and was renamed Cassini Solstice because it will have observed one complete turn of the seasons by May 2017.  It arrived just after Saturn’s northern winter solstice, hence the name.

Cassini’s greatest hits include the discovery and continual study of jets fountaining away from the moon Enceladus. This tiny world has a deep ocean that is kept warm by tidal heating (created by a tug of war between the gravity of Saturn and its outer moons, with Enceladus caught in the middle). The material spraying out from Enceladus has traces of organic chemicals in it, which suggests that Enceladus could be a place where primitive life could form (or may have already).

Saturn itself continues to be a target for the mission. Planetary scientists hope to use mission data to get a clearer picture of the gas giant’s internal structure, and gather more information about its atmosphere.

Want to know more about Cassini and its explorations? The Cassini Solstice Mission has a marvelous Web site where you can find out about the spacecraft, the science, and see many gorgeous images of the Saturnian system. Check it out!

astronomy, gift ideas

Gifting the Universe: Part IV

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 Giving the Gift of Science Research for the Holidays

Give Science!

A couple of months ago I wrote about a startup group called Uwingu. Their mission is to help crowd-fund important science and science education research and training that isn’t getting enough (or any) funding now. The group has been beta-testing a great idea to raise money: naming exoplanets. According to my friend Alan Stern, who is one of the brains behind Uwingu, the group’s original Indiegogo fundraising campaign plus the smaller donations from the planet-naming app have been incredibly successful. “We’ve had more than thirty-thousand site visits and two thousand in small purchases,” he said. Add to that the $79,000+ that was raised in the original campaign and Stern said that there’s more than enough to start funding some science.

“In their visits to the site, people told us they thought the idea of nominating names for planets is cool, but they also wanted to know who we were going to fund,” Alan said. “I’m pleased to announce that we will be funding the SETI Institute, Astronomers Without Borders, the Galileo Telescope Teachers Project, the National Space Society,and the Multiethnic Introduction To Engineering (MITE) Academic Boot Camp at Purdue University.

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Uwingu has added more ways to participate on their site, including a chance for people to buy gift cards that their friends, relatives, classrooms, youth groups and many others can use to nominate planet names for worlds around distant stars. If this appeals to you, check it out! It’s a unique idea and it truly is the gift that keeps on giving.

Stargazing Electronically

I’m a junkie for astronomy programs, particularly for mobile devices. I’ve got several commercially written desktop planetariums such as TheSky (which is a great gift for the stargazer in your life). Recently I’ve been playing with apps, specifically for the iPhone (and can be found in the Apple store). Some are free – such as Moon, by CDV Concepts (it also has a paid “Pro” version — search for it in the app store). It gives you the Moon’s rise and set times, distance to the Moon, and other useful data.

Another one I’ve been using lately is Starmap, which is a handy planetarium for both iPad and iPhone. I’ve had the free version for some time, but there are also paid versions available that add to the first-rate experience for both beginning skygazers and experienced pros. It’s a nice way to take an electronic star chart out with you for skygazing. (Full Disclosure: since finding Starmap and installing it on my iPhone, I’ve been in touch with the developer, and I’m now working on on some new additions for the app, which should be available next year.)

I’ve also been pleased to see such apps as Mobile Observatory come out. I got a chance to see it on someone’s Android during a recent trip and it looks like a very nice “keeper” for folks with devices that say “Droid” to them when they power up.

Desktop planetarium applications are also great ways to share astronomy. As I mentioned, I like to use TheSky from Software Bisque. I also have Stellarium, which is a free, open-source program that runs under a variety of computer flavors. I use it to make star charts for The Astronomer’s Universe, the program I do each month for Astrocast.TV.  There is a mobile version of Stellarium that runs on Nokia N900 and Symbian^3 phones,  as well as Androids. There is an iPhone version, but apparently Apple is not offering it in the U.S. store. Folks outside the U.S. can probably get it.

There are many good apps and programs out there, more than I can write about here. These are a few to get you started, but just put “astronomy apps” in your search engine and you’ll find more of them than you can shake a telescope at!