I know it’s been a few weeks since my last post, and I apologize. Things have been crazy. I couldn’t let this story pass by though.

Lots of planets have been discovered in the last few years thanks to some great advancements in detection techniques. Few, however, are as exciting as the one discovered earlier this year: a warm, rocky planet, with average surface temperatures of 0-40 C (just the right temps for liquid water…and life), located just 20 light years away from our solar system. It’s about 1.5 times the size of Earth, and although it is quite close to its sun (14 times closer than Earth, actually, resulting in a “year” that’s only 13 Earth days long) the temperature of that star is substantially cooler than our own, generating the reasonable temperatures mentioned previously despite the proximity.

This is, by far, the planet most resembling Earth out of all non-Sol planets discovered so far, and it’s practically in our back yard, astronomically speaking. 20 light years is still…well, 20 years away even if we could travel at the speed of light, but considering that our galaxy alone is 100,000 light years in diameter, and the known universe is hundreds of billions of light years across, 20 light years is virtually next door. This kind of proximity means that if there were to be intelligent life on that planet, we could actually send a message and get a reply back in less than 50 years! Far fetched, yes, but fun to think about.

Most of the 200 or so planets discovered outside our solar system have been huge gas giants, which are of course incapable of supporting life. But this new planet, about 1.5 times the diameter and 5 times the mass of Earth, is “either rocky, like our Earth, or covered with oceans.” So in other words, it’s a lot like our Earth now, or it might be like Kevin Costner’s Earth in Water World. Together with the water, the planet’s range from its star (Gliese 581, part of the constellation Libra) puts it in a position to support life — surface temperatures are estimated to be between 0 and 40 degrees Celsius (that’s 32 and 104 degrees Fahrenheit, for the metrically challenged), extraordinarily similar to our own humble spot in the universe.

At “only” 20.5 light-years (or 123 trillion miles) away, it’s almost in the neighborhood, relatively speaking. Keep in mind our galaxy alone is 100,000 light years across, and is only one of millions. In the realm of the known universe, this new Earth-like planet is like a neighbor who lives across the street. If we’ve already found a planet that might be capable of supporting life in the 0.000000001% (if even that) of the universe within a 25 light-year radius of us, imagine what else must be out there.

Source: CNN.

One thing I always attempt to convey to people is the relative size and distance of objects in our galaxy and the rest of the universe — because I think it’s so fascinating how tiny we are and because the sheer scale is almost impossible for our minds to grasp. Well, here is a fantastic video comparison of the sizes of all of the planets in our solar system to our sun to nearby stars to far away supermassive stars — as it zooms out to scale to the larger and larger stars, forget about trying to still see the Earth, forget about seeing our sun, forget about even seeing a star ten times the size of our sun. The other stuff out there is that big.

We seem to be on a Mars streak here. This image was taken by one of those incredible little rovers that operated about 8 times longer than designed, Spirit and Opportunity. It is eerie and beautiful at the same time. I’m pretty sure this is the first time any of us have seen such a sharp image of sunset on another world.

View Sunset on Mars

If you know even an inkling of anything about space exploration, you realize that finding flowing water on Mars, our closest planetary neighbor, would be one of the greatest discoveries of the century. The first photographs of Mars, sent back by our probes in the 1960s, showed a dry, desolate planet. But the latest series of images from the wildly successful Mars Global Surveyor (recent Mars missions have been one of NASA’s few bright spots in the last few years) present impressive evidence that non-frozen water has flowed on the Martian surface within the last 5 years:

“Two of those [gullies] originally photographed in 1999 and 2001 then photographed again in 2004 and 2005 showed changes consistent with water having flowed down the side of the crater. “

This is the strongest evidence yet that Mars is not nearly as inactive as we thought. One theory is that there is an underground water source that periodically breaks through to various parts of the surface — not unlike springs and geysers we have here on Earth. Even critics, while urging caution, call the evidence “compelling.”

Read the whole article

Despite reports last week that we might be increasing the number of planets in our solar system, the IAU has officially declared that Pluto is no longer a planet, closing the door on a 76-year old debate about the status of one of our furthest neighbors. Although it probably won’t be a popular decision among the general public, scientifically I have to agree it is the right thing to do. In recent years it has become clear that Pluto is just one of potentially hundreds or thousands of Kuiper belt objects — a region of space out past Neptune and Uranus that contains lots of what are now known as “dwarf planets” and “solar system bodies.” If we would have kept Pluto a planet and gone with the initial proposal for what constitutes a planet, in a few decades we could have ended up with literally dozens of planets, diluting the significance of the word.

What do you think? Should Pluto, being only a fraction of the size of our moon, have stayed a planet? If so, what would we do with all the other little Kuiper belt objects that would be at least as much of a planet as Pluto?

2500 astronomers from 75 nations are currently meeting in Prague to, among other things, hammer out a universal definition of a planet — a debate which has arisen from Pluto’s much-contested status as a planet — and to vote on a proposal to establish that there are 12 planets in our solar system. If the proposal is approved, the order of planets in our system would be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon, and an as-yet-unnamed body known as 2003-UB313.

The Pluto-Charon distinction is particularly interesting I think, because this in effect would be a “binary planet system” (my own term, not theirs). Charon is currently considered a moon of Pluto. However, it is nearly as large as Pluto itself and as such it doesn’t actually orbit Pluto — they sort of orbit each other, much like stars in a binary star system.

Since Pluto was discovered in 1930, there have been nine planets in our solar system. Should the 12-planet proposal be approved, it will have far-reaching effects on schools, teachers, and textbooks which currently describe the nine-planet system.

Read more at CNN.

A veteran of the space industry, Paul Czysz, says in an interview with PhysOrg.com that with a renewed commitment to nuclear space propulsion, we could reach the edges of our solar system in weeks, instead of the nine or ten years it will take the recently launched New Horizons probe to get to Pluto. Czysz indicates that because of the degrading effects on the human body from long-term exposure to microgravity, the right nuclear powerplant, one which the Russians are already working on, is the only way humans will really be able to explore the solar system. Really an interesting read.