Some extrasolar planets that one might assume are too cold to host life could in fact be made habitable by a squishing effect from their stars, a new study found.
A planet’s midsection gets stretched out by its star’s gravity so that its shape is slightly more like a cigar than a sphere. Some planets travel non-circular, or elongated paths around their stars. As such a world moves closer to the star, it stretches more, and when it moves farther away, the stretching decreases.
When a planet’s orbit is particularly oblong, the stretching changes are so great that its interior warms up in a process called tidal heating.
“It’s basically the same effect as when you bend a paper clip, and it gets hot inside,” said researcher Brian Jackson of the University of Arizona’s Lunar and Planetary Laboratory.
Jackson and colleagues created a computer model to simulate this effect on exoplanets, and found that the process could shift the range and distance of the “habitable zone” around a star in which planets would have the right temperatures needed to harbor life.
Archive for the ‘Science’ Category
Dust – often thought of as an impediment to lunar exploration – could be put to good use to build giant telescopes on the Moon – perhaps some large enough to fill entire craters, says a team of US researchers.
The team, led by Peter Chen of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, US, has devised a simple method to create a concrete-like substance using a mixture of carbon nanotubes, epoxy and a crushed rock material that NASA uses as a stand-in for Moon dust.
Using the mixture, they built a 30-centimetre disc. Then they added more liquid epoxy to its surface and spun it, coating it with aluminium in a vacuum. They believe the process could be scaled up to produce 20- to 50-metre-wide telescopes on the Moon.
New Scientist details a pretty awesome collision in space:
At roughly 8500 by 10,600 kilometres across, it is nearly 15 times the area of the Moon’s South Pole-Aitken basin which, at 2500 kilometres in diameter, is the largest undisputed impact scar in the solar system.
The Mars crater was probably created by an object as large as 2700 kilometres across – over half of the diameter of Mercury. The effects of such an impact would have been catastrophic, says Andrews-Hanna.
“Within the basin you’d have had a magma ocean – it would have been easily several tens of kilometres deep,” he says. “Outside the basin you would have had a tremendous amount of ejecta raining back down on the surface.”
Should we send a mission to Mars that is only one way? A soldier is volunteering to go.
I would prefer that a self-sustaining colony were created. It seems rather futile to go with no hope of return.
Popular Mechanics have a fascinating how-to guide on the Google sponsored prize to get private enterprise onto the moon.
They helpfully conclude:
Realistically, the odds seem to be against a prize-winning lunar mission by 2012. But take heart: Lindbergh and Rutan beat long odds. If you manage to snag a friendly billionaire and follow our how-to guide, there’s no reason you won’t be ready to join the pantheon of aerospace prizewinners.
The Mars Reconnaissance Orbiter managed to snap a photo of the Phoenix during its parachute-aided descent to Mars. Our technology continues to amaze me, if we can have an orbiter of another planet take a photo of another satellite descending to that planet, what can’t we do?
The Earth and Moon as seen from a probe orbiting Mars using a HiRes camera. Amazing.
Looks like progress. Here’s hoping.
Scientists have constructed a custom enzyme that reverses the process by which the human immunodeficiency virus (HIV) inserts its genetic material into host DNA, suggesting that treatment with similar enzymes could potentially rid infected cells of the virus. In tests on cultured human tissue, the mutated enzyme, Tre recombinase, snipped HIV DNA out of chromosomes.
An interesting discovery:
‘Planemos’ is a great word…
The pair belongs to what some astronomers believe is a new class of planet-like objects floating through space; so-called planetary mass objects, or “planemos”, which are not bound to stars.
They appear to have been forged from a contracting gas cloud, in a similar way to stars, but are much too cool to be true stars.
And while they have similar masses to many of the giant planets discovered beyond our Solar System (the largest weighs in at 14 times the mass of Jupiter and the other is about seven times more massive), they are not thought to be true planets either.
I had a listen to Off the Shelf yesterday, where they were reviewing Darwin’s Legacy by John Dupré. A really fascinating 30 minute discussion on creationism and evolution. Professor David McConnell, philosophy lecturer Fr. Brendan Purcell and presenter Andy O’Mahony are well worth listening to.
It’s just a matter of time before a smaller one is found…
An international team of astronomers has found the smallest Earth-like planet yet outside our Solar System.
The new planet has five times the Earth’s mass and can be found about 25,000 light-years away in the Milky Way, orbiting a red dwarf star.
The planet, which goes by the name OGLE-2005-BLG-390Lb, takes about 10 years to orbit its parent star, a red dwarf which is similar to the Sun but cooler and smaller.
It is in the same galaxy as Earth, the Milky Way, but is found closer to the galactic centre.