So-called Goldilocks planets have orbits believed to be in a “habitable zone,” making them candidates for life as we know it. Recently, several new Goldilocks planets have been discovered, many by the Kepler satellite (shut down in May 2013 due to mechanical problems). Here’s a quick primer on the planets as well as some musings as what it might take for us to get there.
Kepler-69c
Distance from Earth: 2,700 light years
Discovered: 2013 by the Kepler satellite
What it’s Like: Kepler-69c is about 1.7 times the size of earth and its 242-day orbit is similar to that of Venus. Its composition is uncertain.
How to Get There: If we could ever engineer a safe way to travel very close to the speed of light, time dilation effects would make the journey to Kepler-69c almost instantaneous for those on board. However, those of us left on earth would never hear from the passengers again.
Gliese 581g
Distance from Earth: 20 light years
Discovered: 2010 by the W. M. Keck Observatory in Hawaii
What it’s Like: Gliese 581g was the first potentially habitable planet discovered (though some still questioned its existence). It is believed to be rocky, with a radius 1.65 times that of earth.
For more, check out this feature about the innovations and conversations surrounding space as the next habitable frontier.
How to Get There: At 20 light years away, Gliese is relatively close. If we had a spaceship that could travel at half the speed of light (traveling faster might be fatal), we could get an astronaut there in about 40 years, earth time. Thanks to the effects of time dilation, the trip would be slightly shorter for those on board.
HD 85512 b
Distance from Earth: 36 light years
Discovered: 2011 with the HARPS telescope in Chile
What it’s Like: Little is known about this planet, except that its mass is about 3.6 times that of earth and that it orbits its star in the habitable zone. Whether it could support life as we know it depends on what it’s made of and what kind of atmosphere it has, if any.
How to Get There: At 36 light years away, this potential outpost is still pretty close. A ship that goes half the speed of light is probably the best bet.
Gliese 667Cc
Distance from Earth: 22.2 light years
Discovered: 2012 with the HARPS telescope in Chile
What it’s Like: Gliese 667Cc has a mass about 4.5 times that of earth and orbits a dim red dwarf sun. It also is probably tidally locked, meaning it has one surface that always faces its sun. Its radius is unknown, so we don’t know how strong gravity is on the planet.
How to Get There: Again, some kind of nonfatal half-light speed space travel might work. Though attempted phone calls with our colonists would suffer from an annoying, 22-year delay.
Kepler-22b
Distance from Earth: 600 light years
Discovered: 2011 by the Kepler satellite
What it’s Like: This was the first planet Kepler discovered. It has a radius about 2.4 times earth’s, and orbits its star in the livable zone, but it’s unclear if its composition is rocky, gaseous, or liquid.
How to Get There: even a ship that goes half the speed of light wouldn’t be able to transport astronauts to Kepler-22b within a human lifetime. Maybe we can put space colonists in suspended animation?
For more, check out this feature discussing space as the next habitable frontier.
