From COSMOS magazine:
The last oasis
by Rick Lovett
Nobody knows what NASA’s New Horizons spacecraft will find when it flies past Pluto in July 2015. But one prospect is that it will reveal our former ninth planet once hosted a subterranean ocean – an ocean that might have lasted long enough to develop life.
It’s not something most people would envision on the icy planet. In 2006, radio astronomers in Hawaii measured the dwarf planet’s surface at a chilly -230°C, only 43°C above absolute zero.
At that temperature, it’s not just water that freezes rock-hard, but also nitrogen and oxygen. Move the Earth that far out from the Sun and most of our atmosphere would fall to the ground as cryogenic snow.
But Pluto may not always have been this cold. At the dawn of the Solar System, relatively fast-decaying atomic isotopes such as aluminum-27 (with a half-life of 720,000 years) may have warmed it substantially, possibly enough to melt it and let the heavier materials settle to the centre. But within a few million years, the supply of aluminum-27 would have run out, and Pluto would have again cooled.
But that may not have been the end of the story, says Geoffrey Collins, a planetary scientist at Wheaton College in Norton, Massachusetts. This is because Pluto has another source of heat – its oversized moon, Charon.
At 1,200 km in diameter, Charon is just over half the diameter of Pluto. It’s also close: at an average distance of only 19,570 kilometers, orbiting every 6.387 days. By comparison, our Moon is about 384,400 km away and orbits every 27.3 days.
Because of their proximity, tidal forces have forced Pluto and Charon to each keep one face permanently facing the other, just as the Moon now does toward the Earth.
By searching through old photos, astronomers have discovered 14 new space objects orbiting near Pluto. Pluto Gets 14 New Neighbors: here.
Pluto’s Atmosphere: Big, Poisonous and Comet-like: here.
Eris and Pluto may have had their differences, but now they have common ground (literally): here.
The New Horizons probe is over halfway to dwarf planet Pluto. The space probe will send back photos of Pluto and perhaps dwarf planets beyond in deep space. A Visit to the Dwarf Planet Pluto and the Space Beyond: here.
Think you know how old the Solar System is? Think again. A Meteorite has shown the solar system is 2 Mill. years older! Here.
Alien Solar System Looks Strikingly Like Ours: Astronomers have discovered at least five alien planets: here.
Japanese space probe reaches Venus: here.
This 1983 Dutch music video asked itself whether there was life on Pluto.
- Dwarf planet Makemake laid bare (bbc.co.uk)
- Debunking end of the world theories (allthatsevil.wordpress.com)
- The unknown solar system (sott.net)
- Pluto – Planet Or Not (colorthoughts.wordpress.com)
- Dwarf planet beyond Pluto is small and barren (cbsnews.com)
- Pluto Atmosphere Larger Than Thought, Study Shows (space.com)