[ad_1]
Copyright of the author
Grace Elizabeth Harrison
Print of the artist: A exomoon orbiting a distant planet
The search for exoplanets, orbiting distant stars, has opened up a whole galaxy of worlds beyond ours. More than 3,700 have been discovered to date, but they can have companions
Since the first confirmed discovery of planets beyond our own solar system more than 20 years ago, we know that our stellar neighborhood Is not unique in the Universe. But now the frontier of exploration is moving again; because where there are planets, there should be moons.
And these moons could be surprisingly similar to Earth.
Why moons?
Up to now, scientists interested in potential living worlds have focused on planets. it might look like the Earth; Currently, our only plan for life.
But what happens if these worlds do not orbit their star, but another planet?
A team of researchers from the University of Queensland Australia is exploring this possibility. exploration of the habitable zone of planetary systems observed by NASA's Kepler telescope.
Also known as the Goldilocks Zone, it is the region around a star where liquid water can exist on the surface of a planet. JPL / Richard Barkus
The team discovered that the expected number of moons in orbit around giant planets in these regions may well exceed that of Earth-like rock planets. This could make it the most abundant potential habitat for life.
"Given the expected number of these moons in the habitable zone of their star, it is quite possible that the first signs of life are outside the solar system, could be found on a moon rather than a planet. looking like Earth, "said lead author Michelle Hill at BBC News
The exomoons could therefore be some of the most important places in the universe.
But they are incredibly hard to find. In fact, no one has yet confirmed a discovery.
"The habitable zone tends to be right on the edge of our current detection methods," says Dr. Stephen Kane, another author of the study. Spotting the planets out there is pretty tricky, but moons are something else.
Copyright of the Image
NASA / Science Photo Library
Being in the habitable zone can dramatically change the surface of an image. planet
Dr. David Kipping, who heads a team at Columbia University in New York, is interested in the idea of exomoons since he's a student.
"There are not many of us looking for these things, but I'm sure as soon as we start to find them, there will be more people who will join the hunt" , he told the BBC
. "Trying to understand … how common [they are] will give us an idea of the originality of the solar system."
How are moons formed?
Copyright of the Image
NASA
Most moons are thought to be formed from the remains of their mother planet.
In our solar system, the large family of Jupiter moons probably formed from the accumulation of this material when the planet was young.
NASA Photo Gallery / Science
Moon of Neptune Triton
Moons can also begin as dwarf planets or asteroids orbiting their star, but later captured by planets with a much stronger gravitational attraction.
It is thought that this is the case of Triton. Neptune planet, and may have already lived in the Kuiper belt – a remote area of the solar system beyond the orbit of Neptune
Copyright of the photo
Science Photo Library [19659014] Our own Moon formed by a giant impact. When another great body collided with the early Earth, the resulting debris gathered to create the Moon.
The Earth and the Moon actually form an unusual couple within our own Solar System
And it's not really obvious if it's an empirical rule or if it's extremely unusual in the universe, "says Dr. Kipping
What makes a moon a good home?
Well, size matters. You could certainly have a giant planet that had moons of similar size and mbad, say, in Mars, which would create a lot more habitable conditions, "says Dr. Kane.
An atmosphere can also dramatically increase a planet's ability to house life, and bodies must reach a certain size to maintain one.
"One of the major impacts on the planet's ability to conserve its atmosphere is how far it is from [star] because the [star] emits what we call a solar wind, which tends to erode a "
The magnetic field of a planet can protect its moon against the severe solar wind.
In addition to water, life also needs energy, which can to be provided by the gravitational pull of a planet that squeezes MOON – as it does with highly volcanic Io
Copyright of the photograph
PHOTO LIBRARY OF NASA / SCIENCE [19659004] Image caption
Jupiter pulls and stretches the tiny Io, causing the heat that feeds his volcanoes
So when are we going to find the first exomoon?
Dr. Kipping's team has identified the exoplanet Kepler 1625b as a potential candidate to host an exomoon, but they have not yet been able to confirm a discovery.
Planet of the size of Jupiter, she is as far from her star as the Earth is from the sun.
Copyright
Grace Elizabeth Harrison
Artist Print: Kepler 1625b Exoplanet Can Accommodate a Moon
But finding life is not easy
However, finding even clues about living on an exomoon will be extremely difficult.
"In the solar system we have no idea if [icy moons] has life under the surface or it is very, very difficult, even when we live next to these objects, to evaluate this that's happening under the surface of the ice … Imagine doing it from light-years away, "says Dr. Kipping.Despite the challenges, Professor Giovanna Tinetti, exoplanet researcher at the University College of London, think it's better to keep an open mind.
"I think we need to be open when it's about habitability, [and] not staying attached to the … view that you must have a planet that is as big as Earth, at the same distance from the Sun with a star that is exactly like the Sun.
"I hope life is a bit more original than that."
Source link
