Super-Earths Discovered Orbiting Nearby, Sun-Like Star

likuidkewl writes "Two super-earths, 5 and 7.5 times the size of our home, were found to be orbiting 61 Virginis a mere 28 light years away. 'These detections indicate that low-mass planets are quite common around nearby stars. The discovery of potentially habitable nearby worlds may be just a few years away,' said Steven Vogt, a professor of astronomy and astrophysics at UCSC. Among hundreds of our nearest stellar neighbors, 61 Vir stands out as being the most nearly similar to the Sun in terms of age, mass, and other essential properties."

Comments

Yes, nearby

[elrous0]

Yes, a mere 28 light years away. So all we need to do is get in the fastest spacecraft we've ever built and we can be there in just about 150,000 years.

Who's coming with me?!?!?

Re:Yes, nearby

[CrimsonAvenger]

Slow and steady acceleration wins the race. You're not going to do that with a chemical rocket, but with an on-board nuclear reactor and a few advancements in ion propulsion or vacuum propellers, we could make the trip. We could easily launch a probe to start making the journey in the next five years, if we allocated the budget to do so. Humans could make the trip as well, given the right accommodations--only a few years would be passing on-board.

Not so few as you might think. At 0.01G, we're talking about 100 years as measured by clocks on the ship.

If we define "a few years" as "five or less", we'd need about 1.5G constant boost to reach 61 Virgo in "a few years". Which, by the by, translates to a mass ratio of about 2700 if we're using a photon drive, or a number that's the next best thing to infinity if we're using any drive we can foresee in the next couple decades.

Re:Yes, nearby

[KitsuneSoftware]

Unfortunately, it's a lot further off than you think. To accelerate to near the speed of light, regardless of the method, requires an enormous level of energy: for comparison, the space shuttle (68,000 kg) going at half the speed of light will have a kinetic energy of 9.455x10^20 joules. Again, for comparison, the total solar flux of the earth is about 1.75x10^17 watts, while total human power consumption is around 16x10^12 watts.

Re:Yes, nearby

[Gospodin]

That is an ion engine. My back-of-envelope calculations say that accelerating to .0002c and back to rest requires an Isp of about 5300 if you assume a mass ratio of 10:1. (Which is about as high as you can expect with current technology.) You can do a little better with staging, but not orders-of-magnitude better.

If you can improve your Isp to, say, 50,000, which is well beyond current technology, then you could accelerate to almost 0.002c. Relativistic effects won't be really evident until well over 0.2c (at that speed it's only a 2% time dilation). We're not close to rockets that can attain such speeds.

Improving the mass ratio is even less helpful, btw, since that's a logarithmic factor. An Isp of 50,000 with a mass ratio of 100 still only gets you to 0.004c. I suppose it's conceivable that an interstellar ship that needed almost no structure could have an extremely high mass ratio, but you can see how ridiculously high it has to be to matter.

The only way we're going to send starships at relativistic speeds is to use (i) some form of non-rocket propulsion, like solar sails or those reactionless Casimir-effect thrusters or some other exotic method, (ii) something with a truly enormous Isp. Current ion engine tech tops out at about 30,000 s, and even nuclear pulse tops out at 100,000 s.

Re:Yes, nearby

[CrimsonAvenger]

"If we stick with only 1.0G, then we wouldn't need artificial gravity for the people on board."

Considering their new home has five earth masses at the very least, they might as well get used to 5.0G. Ouch.

Umm, no. Five Earth masses at the same density as Earth means about 1.7G.

Double the density, and the planet pulls about 2.7G, but has stopped being Earthlike (density as high as silver?! ouch!).

Re:mmmm

[Daimanta]

How's that? I'm sure that it's possible to find at least 61 virgins on /. In fact, I think you are the right place if you're looking for virgins.

Wow, a confirmation

[MillionthMonkey]

Why is everyone surprised that super-earths are orbiting other stars? I've always wondered that.

Anyway in case anyone hasn't RTFA (or noticed the light-gray on white links at the top of the oklo.com page) you yourself can help them search for nearby earths by downloading the tool at http://oklo.org/downloadable-console/ while you're still unemployed.

Re:Wow, a confirmation

[TropicalCoder]

There is nothing in the article to support the title, "First Super-Earths Discovered Orbiting Sun-Like Stars". First they say "These detections indicate that low-mass planets are quite common around nearby stars." and then later "The inner planet of the 61 Vir system is among the two or three lowest-amplitude planetary signals that have been identified with confidence". and finally, "The researchers said they cannot tell yet if HD 1461b is a scaled-up version of Earth, composed largely of rock and iron, or whether, like Uranus and Neptune, it is composed mostly of water."

I don't see anything in the article to justify calling these planets "Super-Earths", which is a stupid term anyhow, since there is only one planet Earth and we are on it.

Re:28 light years

[Hurricane78]

Bet that bacteria did not think about that either.

You know... cause they’re bacteria! ^^

72-Virginis

[sanman2]

Osama Bin Laden may be hiding in neighboring star system, 72-Virginis

Re:Duh!

[girlintraining]

Bacteria are really tiny, you know, and dinosaurs were really big.

And you're the result of millions of years of evolution since then? I'm disappointed.

Re:mmmm

[Anonymous Coward]

Wait, you think oral sex is gross? I agree that clean people and vegans actually do taste better. It's a lot of fun, try it some time!

Vagina. And. Penis. Licking. Good heavens, it's as natural and delicious as apple pie.