a question about the planets?

Question

Have we discovered life on planets? i've heard that bacteria or something was found on planets but have we found anything else, any plants?
and another question, i've heard that we've found planets or a planet with water on it, how did it get there, how was it formed? or how do we think it formed?

Answer 1

To take the second set of questions first:

GLIESE 581c

This newly-discovered planet where life is thought to be feasible orbits Gliese 581, one of the nearest 100 stars to us, 20.4 light years away.

The new planet was found on 23rd April 2007 by a team led by Stephane Udry of Geneva University, The observatory they used was high in the Chilean Andes, where good viewing conditions would be available.

It is in the constellation Libra. It is the 87th closest star system to us. Its star (a Red Dwarf) is too faint to be seen with the naked eye, however. Its magnitude is 11.56.

What is unusual about Gliese 581c, amongst the 241 planets we have found orbiting other stars is

a) it is a rocky terrestrial planet not a gas giant

b) it is in the habitable zone i.e. with a temperature range at which water would be a liquid not ice. This is felt to be essential if it is to harbour life.

c) it has a radius 1.5 times that of earth (and a mass 5 x earth), the smallest yet,

(d) It orbits very close to its star (as the star, a Red Dwarf, is much cooler than our Sun, the planet needs to be nearer in to be warm enough to be habitable) and its year is a mere 13 Earth days in length.

There are two other planets in the same stellar system, one even further in (Gliese 581 b) a Neptune-sized planet of 17 Earth masses found in 2005 and one further out (Gliese 581 d) a planet of 8 Earth masses found in 2007.

The big question marks are:

(a) it is big enough to retain an atmosphere but is it breathable by humans?

(b) does it actually have (a plentiful supply of) water?

(c) how would we get there? (our present fastest rockets available would take 300,000 years)

(d) is the planet gravitationally locked to ts star, such that the same side of it always faces the star?

Many of the questions people will inevitably ask can only be answered when we can send an unmanned probe there. Meanwhile other planets will be found even nearer to us. (We know of a planet 10.5 light years away around Epsilon Eridani (the 9th nearest star) and 3 around Gliese 876, 15 light years away.)

Wilhelm Gliese was a German astronomer, best known for the Gliese Catalogue of Nearby Stars that he compiled.

YOUR SUPPLEMENARY QUESTIONS:

No, we don't know that it definitely has water, yet. We only know that if it were to have water, the temperature and climate would be such that the water would be in liquid form. That is essentially the difference between being in the habitable zone and knowing that anything is inhabiting the planet.

It is thought water came to earth from comets' tails that melted and perhaps the process is similar elsewhere in the universe.

It is probable that planetary formation occurs similarly elsewhere in the universe, Early in its life, a star spews out excess gaseous material which then cools and coalesces to form planetesimals, and by gravitational attraction and accretion, these become lumped together to form planets.

The ingredients that go into the pot to form the planets very much depend on what the star inherited from its surroundings when it formed. It is thought that the Sun benefitted from a nearby supernova remnant, Heavier elements can only form via nucleosynthesis inside a supernova, and heavier elements are needed to be able to have rocky planets and to be able to have life forms develop on them.

The later a star is formed (in the life of the Universe), the more chance of it benefitting from such windfalls. The Universe is 13.7 billion years old. The Sun is 4.57 billion years old and Gliese 581 is a little younger than that at 4.3 billion years old.

YOUR FIRST SET OF QUESTIONS

No, we have not as yet discovered life on any other planet nor have we discovered irrefutable evidence that life once existed on some other planet, No plants, no bacteria, no moss and lichens, not even a solitary amoeba. As yet.

As far as we know we are still alone in the universe. But hopes are being raised as regards landing on Mars, and the following water sources:

Encaladus spews out a water geyser near its South Pole. Titan has liquid lakes on its surface. Europa has an under-the-ice ocean, kept heated by the gravitational pull of Jupiter. It is believed Ceres has more fresh water in its interior than exists on earth.

We may have to drill down to reach, harness and utilise these resources.

Answer 2

Human Planet

Answer 3

Ya there were fossils to proove that bacteria used to live on Mars and they also found crystalized water, the answer to the second question i am not sure but i know they found a planet that had the same atmosphere as earth and could hold water but they havent reached it so they are not sure if there is actually water

Answer 4

"...Have we discovered life on planets? i've heard that bacteria..."

Several years ago a team of scientists claimed to have found fossilized microbes (..fossilized life..) inside a meteorite from Mars that had been on Earth. Right now there's no total agreement on whether or not these are truly microbes. More details here ==>http://www.space.com/scienceastronomy/solarsystem/carbonate_water_020116.html

"...i've heard that we've found planets or a planet with water on it, how did it get there..."

There are a couple of moons in our own Solar System that have what is believed to be water or water ice on them. Mars has water ice in its north and south poles and possibly small amounts of liquid water on its surface. Additionally a planet lying some 20.5 light years away was found that could have (..not definitely..) conditions in which water could exist.

Answer 5

So far, we have not discovered life on planets. People are sending space probes to Mars because there is extremely strong evidence that it could have had a warm, moist atmosphere like Earth today. We have found ice on the moon, there is also strong evidence that the moon could have had an ocean before. Scientists say that there could have been life on Europa or Titan, Saturns moons.

Answer 6

I believe that they found some sort of bacteria on Mars, and that a moon was found around another planet that they thought could support life, but as far as I know that is just conjecture.

Answer 7

Yes there was fossilized bateria found on mars. But as of now no structural evidence has been found. But it may be possible (scientists say) that there might be life on one of jupiter or saturn's moons, especially Eruropa and Titan. Underneath their frozen seas life may exist in a more stuctural form. I suggest that you read, Faint Echoes, Distant Stars (by Dr. Ben Bova). And the planets with water on them, the most likely cause is that comets which hit the planets depsited ice which then melted. But as of now, in the solar system, Earth is the only one with liqid water. Mars once had rivers but they are gone now. But there may be liquid water underneath Europa, or titan's frozen seas.

Answer 8

There is no empirical evidence for there being life of any kind - microbiological to technological - on any celestial body other than Earth.

There is no reason to suspect any body with liquid water would not harbor at least microbiological life. A sloppy mix of water, ammonia, methane, hydrogen sulfide, and rock plus energy begets biochemistry within a week.

Google Images
miller abiotic 1600 hits

Add a billion years of patience for abiotic chemistry to get clever about itself - life.

Answer 9

For the answer to all of your questions such as this, please do a serach on the Internet using the key words:

Curious About Astronomy

That will lead you to a site developed by Cornell Uuniversity for inquisitive minds such as yours. They have key words there on that site which lead you to extensive discussions and photos of space, planets, comets, meteors, asteroids, with all manner of illustrations to help you out. etc.

i think you will be very pleased with what you find there. It is most extensive, and has a chat line/blog there also.

Answer 10

I don't know the first question but i od the second one.
astronomers have found a planet that has ice on it. There are many planets that have ice on them. It's just becuase they are too far from the sun to become liquid.