News Discovery Technology: “Another Earth”, “Earth 2.0″. What are we to expect from it?

Friday, July 24, 2015

“Another Earth”, “Earth 2.0″. What are we to expect from it? – Gazeta Wyborcza

Visualization planet Kepler-452b (NASA)

At yesterday’s conference, NASA announced the discovery of “cousin of the Earth”. Slightly older and more but orbiting Sun-like star at a similar distance as Earth. We are already getting ready to relocate?

Article opened within the limits of free digital subscriptions

1 ->

The planet Kepler-452b, which the Americans have announced the discovery on Thursday late afternoon, can be reached 1.4 thousand. light years. And very Earth-like.

It has a diameter greater only about 60 percent. of our planet and orbits the star very similar to the sun. Most interesting, however, is that it orbits within 385 days. Since the orbital period determines the amount of orbit, we know that this distance is very similar to the one in which the earth revolves around the sun. This means that the surface of the newly discovered planet is neither too cold (as on Mars) nor too hot (as Mercury) and can there be liquid water.

At least in theory. Similarities in fact tend to be quite deceptive. And often, the devil is in the details.

volcano on a volcano?

If Kepler-452b has a structure similar to the Earth, which is rocky, with its size must be at least five times more mass. As a result, could no longer maintain internal heat. According to experts from the geophysics from NASA, this has an impact on the tectonics of the planet and should be on the expected larger than Earth’s volcanic activity. Gases released by volcanoes can and make that the greenhouse effect is greater there than on Earth. Hence, even though the same amount of radiation received from the sun, on the surface of the newly discovered planet may be much warmer.

How much warmer, we do not know. But we know that the Earth’s atmosphere is very sensitive to the really small fluctuations of greenhouse gases. When the carbon content of 200 ppm (parts per million) on the Earth followed glacial. At 400 ppm, as it is now, it is getting tropically hot and glaciers, even those at the poles, begin to disappear.

Perhaps the older and larger “cousin of the Earth” is more like a but-hot Venus, where temperatures soar several hundred degrees, and all the water has long since evaporated.

Do we have a chance to send a probe there once to check it out?

When we get there ?

1.4 thousand. light years is almost unimaginable distance. If the distance from the Earth to the Sun imagine as one meter, then this ratio Kepler-452b would be 100,000 kilometers away.

At this time, the Earth farthest object is launched in the 70s, Voyager 1, which any while leaving the solar system. Speeding at breakneck nearly 1.4 million kilometers a day. But even at this rate journey to the “second Earth” he would take her some 25 million years.

What are the alternatives? – NASA takes on the construction of plasma ion engine (variable specific impulse magnetoplasma rocket), sometimes called drive twenty-first century. With such an engine to a newly discovered planet get in … 3.5 million years.

There are of course concepts sci-futurological but having a scientific basis. For instance, in 1947. Polish mathematician Stanislaw Ulam, who after the war worked in the US over the thermonuclear bomb, proposed that in interstellar space behind a ship dispose of a small nuclear charges. Their shock wave rozpędzałaby ship to great speed. This was based on the Orion project, on which NASA began working in the late 50s was shelved with the signing of the treaty to ban nuclear tests in the atmosphere and space. But in the late 80s, when President Ronald Reagan tried on the “Star Wars”, reverted to the idea. NASA and the Navy have developed a mission Longshot, or “long shot” – probe was to fly to the nearest star Alpha Centauri us, distant 4 light-years, and was to be driven just by micronucleus explosions. Explosions small spheres with helium and tritium ignited by laser beam.

It was estimated that it would reach speeds of over 13 thousand. km / s, or nearly one-twentieth the speed of light. Would have a chance to get to Alpha Centauri in less than 100 years. Maybe someday we will use this idea. But the Kepler 453b, which is 350 times farther away, even with such dizzying speed journey would take still 35,000 years.

Yet for a long time so we are left with only the observation of a distant cousin of the Earth by better and better telescopes.

However, I’m not letting nose fifth

The fact that so soon discovered a planet similar to Earth – after all we are looking for planets around distant stars just less than a quarter of a century – should be tuned us with optimism. It is true that we are looking for planets only in a very small part of our galaxy, but we know roughly the size and we can estimate how many planets are in the galaxy. Astronomers talk about difficult imaginable number 100 billion.

We know that several thousand planets that have already discovered, several are similar to Earth. This would mean that the Galaxy statistically speaking, there should be tens of millions.

If we divide this number by the volume of the Galaxy, it turns out that planets similar to Earth orbiting the Sun-like stars should be around 60 in a radius of 30 light years. At least, experts estimate from NASA. And that is the distance you may be able to beat us once. Ba, from this distance, we may be able to see her face. And it’s still in our lifetime. Are you yourself are able to conceive?

You really live in interesting times.

We already know more than 4.5 thousand. objects orbiting the star. While calculating that does not confirm some of them remain “candidates on the planet”. In the figure below, the vertical axis marked the size of the object on the horizontal its orbital period around the star (which determines the distance at which the planet orbits its sun). Earth objects are relatively few, but probably due to the fact that bigger, more massive objects much easier to observe.