Which celestial bodies are more likely to host extraterrestrial life: Saturn’s hazy moon Titan and water-spewing moon Enceladus, or Jupiter’s icy moons Europa and Ganymede, which may have liquid oceans beneath their frozen crusts? That’s the difficult question facing NASA and the European Space Agency (ESA) as they try to decide where to send the next planetary probe. By the end of this month, agency officials plan to pick a destination for a massive mission, costing nearly US$4 billion, to be launched around 2020 for the distant reaches of the Solar System. The battle pits Titan, which recent discoveries have made the cool new kid on the block, against Jupiter’s moon Europa, which has long sat atop community wish lists [Nature News].
In advance of that decision, the space agencies have released details of the dueling proposals. The potential Saturn mission would follow up the remarkable discoveries made by the Nasa/Esa Cassini-Huygens mission which continues to operate at the ringed planet…. Cassini has sent back data that indicates Titan is akin to a primitive – albeit frozen – Earth. It has a thick atmosphere and is rich in organic (carbon-rich) molecules [BBC News]. The plan calls for an orbiter that would release a hot air balloon to drift in Titan’s hazy atmosphere and would drop a lander to the surface, where it could float on one of moon’s lakes of liquid ethane and methane. The orbiter would also dip into the atmosphere of Enceladus, which has fired imaginations with the revelation that it has geysers that spew jets of icy water into space.
But the arguments for exploring Jupiter’s moons are just as compelling. In 1995, the Galileo probe began an 8-year tour of Jupiter’s system, during which it snapped the first close-ups of Europa’s scarred surface. Analysis of a magnetic anomaly soon revealed the moon’s most astonishing feature: that eggshell of ice is thought to enclose a warm, salty ocean. Scientists immediately clamoured to return [Nature News]. Supporters of a mission to the Jovian moons say that an orbiter equipped with an ice-penetrating radar could settle the question of how thick Europa’s icy shell is–and crucially, whether it’s thick enough to shield primitive life forms from the punishing radiation coming from the sun and from Jupiter’s magnetosphere. Scientists would also like to study the larger Jovian moon Ganymede because of its intriguing magnetic field.
The radiation that a Europa orbiter would have to withstand may be a sticking point: NASA is developing technology to shield the orbiter’s instruments, but it would be expensive. The Europa orbiter must fit within a NASA cost envelope of $2.9 billion, while the ESA contribution, the Ganymede orbiter, must cost less than €650 million ($860 million). At those prices, a landing element, or even an ice-drilling cryobot, is impossible. But [NASA scientist Bob] Pappalardo argues that sending a Europa orbiter now could pave the way for a future lander — by scouting for the smooth pavement. “We’re ready to go to Europa now,” he says, “and we’ll be ready to do Titan next” [Nature News].
Related Content:
80beats: New Evidence of Hospitable Conditions for Life on Saturn’s Moons
80beats: Geysers From Saturn’s Moon May Indicate Liquid Lakes, and a Chance for Life
80beats: Hydrocarbon Lake on Saturnian Moon May Be a Hotspot for Alien Life
DISCOVER: Water World takes a look at Europa
DISCOVER: Jupiter, Not Bust chronicles the Galileo probe’s Jupiter observations in 1996
Image: NASA/ESA
January 22nd, 2009 at 5:00 pm
I’m on the fence. Though, I think a mission to Titan would be most beneficial, mainly because of the unique position the moon happens to currently be in, what with its similarities formation-wise to Earth, and the possibility of life being able to flourish in a Methane/Ethane rich environment. Seeing as how we’ve already successfully entered Titan’s atmosphere and acquired pics from the surface, I think that’ll be the first target pursued.
January 23rd, 2009 at 12:15 am
Maybe we can move to Titan when Sol goes red giant and eats earth, but warms the outer solar system up for us. Maybe that’ll turn Titan into a balmy little place.
January 23rd, 2009 at 8:05 am
As far as radioactive shielding is concerned, the “invisability cloak” seems to hold promise as an inexpensive solution to the problem.
January 30th, 2009 at 8:31 pm
I think that it cool how they can keep NASA so updated on everthing. Supporters of a mission to the Jovian moons said that a orbiter equipped with an ice penetrating radar could settle the question of how thick Europas icy shell is and crucially; whether its thick enough to shield primitive life forms from the punishing radiation coming from the sun and from Jupiters magnetosphere. I think that its really cool how they can use a radar to tell ho thick Europas icy shell is..
February 1st, 2009 at 9:39 pm
well i think they should get over the extra terresrtial life form thing cause ,if they still cant prove it they shouldnt waste money on finding what dosent exist.If they want to find out if those moons could support life they should drop off some monkeys and lab rats and base their research off that.i also think if they had to go into space they should go to titan because if we can send a probe their whats to say we couldnt send all our nuclear waste up their and shove it into the ethane and methane lakes?
February 3rd, 2009 at 2:54 pm
What I find interesting is that they shouldnt keep looking, and searching for extrateresrtail life forms, because in the end it will lead them right back to were they started. And to experiement to see if life is sastaunable on that palnet they should use something living and set it on the planet. To see if it survives. And base most of there research on that. And I think it is neat how NASA is always updated, but yet I think they should take there time making sure that what they are post, and saying is true. And the journey of Titan will be rather difficult I personally think that we should put it off. Atleast for the time being. Due to financial issues. And such. Even though it would be neat and very interesting to explore into this whole idea further I think it might be a waste of time.
February 3rd, 2009 at 2:56 pm
What I find interesting is that they shouldn’t keep looking, and searching for extraterrestrial life forms, because in the end it will lead them right back to were they started. And to experiment to see if life is sustainable on that planet they should use something living and set it on the planet. To see if it survives. And base most of there research on that. And I think it is neat how NASA is always updated, but yet I think they should take there time make sure that what they are post, and saying is true. And the journey of Titan will be rather difficult I personally think that we should put it off. At least for the time being. Due to financial issues. And such. Even though it would be neat and very interesting to explore into this whole idea further I think it might be a waste of time.
(REPOST, Spelled check)
February 5th, 2009 at 3:13 pm
They shouldn’t keep looking if we have already proved that there is no extraterrestrial life. We should save our money, and spend it on something we haven’t yet discovered or something that needs more information to prove what they believe in.
February 5th, 2009 at 3:15 pm
I think it’s pretty interesting because it’ll be cool to see what it’s like to see the surface of something far in space like a moon from Jupiter or Saturn. But i dont’t really believe that they will find life forms there but it’ll be interesting to find out.
February 9th, 2009 at 12:09 pm
I think this is really interesting but dumb. I think it’s a waste of four billion dollars just to find small little mirobial extraterrestrial life ! I personally think that they should start saving their money and wait a few years and maybe whatever it was that they found could grow bigger.
February 17th, 2009 at 5:34 pm
I think there is no point spending all this money on space because we need to have some for earth, too. Because the earth is where we are currently living. Paying that much money seems like a dumb thing to do. There are way more important things than moons and planets.
March 2nd, 2009 at 8:42 pm
i thimk europa holds the most promise for a planet that is able to sustain life. perhaps a submerged caplsule could be a tempeorary home for astronauts studying the planet
March 3rd, 2009 at 2:00 am
I cant belive the lack of intelligence in these posts. If you don’t have knowledge on something, you shoulden’t be suggesting things. Are any of you scientists? NO! So don’t post unless you have a clear idea of what is being discussed.
March 31st, 2009 at 12:51 am
“I cant belive the lack of intelligence in these posts.”
I agree with the above! What are you people talking about?!? Someone said to put life from earth, such as rats, on the surface of titan? That is absurd.
“well i think they should get over the extra terresrtial life form thing cause ,if they still cant prove it they shouldnt waste money on finding what dosent exist.”
You don’t know that it doesn’t exist, that’s the point. The point of making a new discovery. If a small microorganism was found anywhere outside of earth’s atmosphere that would open up BILLIONS of possibilities. I don’t think any of you realize that.
We as humans know so little about what happens in the universe, sometimes people don’t appreciate that.
August 19th, 2009 at 10:53 am
Neither Jupiter’s stunning moon Europa nor Saturn’s Titan harbors life and never has. The only object in this sun system with liquid water (other than negligible amounts at glacier melts) is Earth. Galileo’s 1995 pics are exciting, but the icy crust of Europa does not cover liquid water oceans. That hypothesis is wrong. Titan’s ethane and methane lakes are stunning, but Titan is abiotic like all other bodies in this sun system other than Earth. RNA and the more complex DNA do not just pop up on their own when there is liquid water, as many astrobiologists seem to think. It takes more than water for life to emerge. But the cosmos in general and the Milky Way galaxy are teeming with life and with intelligent species. I support the proposals to land probes on Europa and Titan, as these are exciting moons deserving of scientific investigation. But don’t expect to find life in this sun system other than on Earth. You won’t. Having said this, ET spacecraft and astronauts are real (just listen to what NASA astronauts have observed including on Apollo 11). But all of them originate from outside of this sun system.
January 8th, 2010 at 9:39 pm
first i think europa might they could be life out there in the galaxy or universe