Nasa: discovery of a new planet that could harbor life

If you ask astronomers how many planets in the universe harbor life, they will likely say there are only two possible answers: one or infinity. We can rule out zero, thanks to the decidedly alive Earth, which means that so far one is the answer. But if we discover another, the answer jumps straight past two to infinity. The reason: You can posit a universe in which the confluence of factors that made life possible here are so complex that the right roll of the dice could statistically happen only once. But if it can happen more than once, why should there be any limit? (Actually, something could be so rare in nature that it happens only two or three times, but the overall zero-one-infinity idea originated with theologians debating atheism, monotheism and infinite polytheism, and planetary scientists just kind of liked it and claimed it as their own.)

Humans have always hoped for infinity, since it would be an awfully lonely universe if we’re the only planet with its porch light on. And with the recent explosion in the discovery of exoplanets (planets orbiting other stars), astronomers now believe that virtually every star in the Milky Way is circled by at least one planet. There are up to 250 billion stars in our galaxy and about 100 billion other galaxies out there—trillions upon trillions of places life could be thriving.

In their search for such worlds, astronomers focus their energy on Earth-like, rocky planets, with atmosphere, water and an orbit that places them in the so-called habitable zone, where temperatures are just right for the water to exist in liquid form. Last week, NASA announced a jackpot: an Earth-sized world in the habitable zone of a hospitable star, just 100 light years from here. The star is known as TOI 700 and the planet is TOI 700 d, the outermost of a litter of three planets. TOI 700 is a red dwarf, a class of stars smaller and cooler than our sun, which were at first thought of as poor candidates for nurturing life, due to their relatively low temperature. But the fact is, as long as the planets orbit close enough to the hearth of the star, they get plenty of light and warmth—and TOI 700 d does.

It was the Transiting Exoplanet Survey Satellite (TESS) that discovered the star, and the Spitzer Space Telescope that took its environmental and chemical measures. TESS uses four on-board telescopes to look for the slight dimming in the light of a star when an orbiting planet passes in front of it. Spitzer makes its observations principally in the infrared spectrum, which is an indicator of heat that can, in turn, yield a lot of data on composition and chemistry.

TOI 700’s other two planets orbit too close to the star’s fires for water not to boil away. But TOI 700 D, which is about 20% larger than Earth, orbits its sun at a distance of about 15 million miles—that’s far closer than Earth’s 93 million miles from the sun, but given the lower temperature of a red dwarf, the planet receives roughly 86% of the stellar warmth Earth does.

Computer models for conditions on TOI 700 D based on that suggest the planet is tidally locked, meaning it keeps the same face turned toward its sun all the time. But an atmosphere could nonetheless help distribute heat to the dark side, and temperatures would certainly be comfortable in the border regions between light and shadow. In one model, the planet is watery, with an atmosphere that is principally carbon dioxide—similar to ancient Mars before it lost its atmosphere and water. In another, the planet is dry and cloudless. Overall, researchers modeled 20 different versions of TOI 700 d, any one—or none—of which could be correct.

That very wealth of possibilities is a statement both of our imagination and our ignorance: we can gather the data we need to imagine more than a dozen and a half plausible versions of the same planet—but don’t have enough data to say which, if any, is correct. And as for the possible existence of life there? We can’t even guess. But exoplanet science is a brand new game. It was only in 1992 that the first exoplanet was discovered. At this point, we’ve not even moved past the training-wheels stage of studying them. If TOI 700 d proves anything though, it’s that there may be extraordinary potential on an extraordinary number of worlds. If you’re a betting person trying to answer that astronomers’ multiple-choice question, consider putting your money on infinity.

The planet Mars is losing water faster and faster

Contrary to what had been established, the precious liquid present in the form of ice evaporates faster than expected

The question torments all astronomers around the world. Will humans find water on Mars if they ever manage to set foot on its soil? If scientists knew that the precious liquid had gradually disappeared from Mars over time, a recent study claims that the process would actually be much faster than expected and that the water would evaporate at an underestimated speed, explains The Independant. And it is now the whole project of a human expedition to the red planet that is called into question. Water evaporates when the sun transforms its molecules into hydrogen and oxygen atoms.

The planet's gravity is then unable to hold them back and they disappear into space. There was a time when Mars was filled with water as several studies have shown. Rivers and lakes were part of the landscape. NASA predicts that the first Mars expedition is expected to materialize within ten years. However, we must qualify. There is nothing to indicate that there will be no more water when man takes his first steps on Martian soil. The evaporation process indeed spans several million years.

With the seasons

The study was carried out using data collected by the Trace Gas Orbiter probe launched in March 2016 and which has been crisscrossing the atmosphere of the red planet since October 2016. On the North Pole of the sun, ice is melting at a speed important, especially when the Sun is closest. The presence of water is intrinsically linked to the discovery of life.

"Not enough, therefore, to question the plans of NASA which plans a human expedition during this century," says Franck Montmessin, French researcher who participated in the study,  “By analyzing the TGO data, we could see that the loss of Martian water is much faster than we thought. And, above all, that it has a cyclical, seasonal rhythm, which depends on the solar lighting at the level of the poles, "he explains.

Two habitable super-Earths discovered around nearby stars

Two recently detected exoplanets, named GJ229Ac and GJ180d, will constitute new prime targets for the search for life.



You probably won't remember their name, but astronomers are not going to forget them. The two exoplanets that researchers at the Carnegie Institution have just discovered have remarkable characteristics. Called GJ229Ac and GJ180d, they are both of a size close to that of Earth, in other words probably rocky, and located in the habitable zone of their respective stars, that is to say capable of harboring l liquid water. These first two elements therefore make them planets theoretically suitable for the appearance of life. But that's not all…

If they deserve so much attention, it is also because they orbit around stars that are closest to our Sun. Indeed, GJ229Ac and GJ180d orbit around two red dwarfs, Gliese 229 (GJ229) and Gliese 180 (GJ180), located respectively 19 and 39 light years from us. If this may seem enormous, it is very little on an astronomical scale. Thus, the closest star to the Sun, Proxima Centauri, is already 4.2 light years away from it. On the scale of the Milky Way, which is approximately 100,000 light years wide, these potentially habitable super-Earths are therefore found in the suburbs of the solar system. For all these reasons, even if the hospitality of the planets orbiting red dwarf stars is still under discussion, it is a safe bet that GJ229Ac and GJ180d will be among the first targets of telescope observations. new generations, such as the James-Webb telescope, which is scheduled to start operating in March 2021.

While waiting for these state-of-the-art devices to look into their case, scientists already have some information on these almost neighboring worlds. The mass of GJ229Ac and that of GJ180d are equivalent to 7.9 and 7.5 times that of Earth. The first revolves around its star in 122 days and the second in 106 days. Finally, while GJ229Ac is the potentially habitable super-Earth orbiting a star which has a brown dwarf companion closest to us, GJ180d constitutes the “temperate” super-Earth whose orbit is not locked. (unlike the Moon which always presents the same face to the Earth and the majority of exoplanets orbiting red dwarfs) closest to us. A feature that further increases the chances that GJ180d can shelter life

SpaceX: last successful test before sending a manned flight to the International space station

Elon Musk's space company successfully simulated, at the Kennedy Center in Florida, the emergency ejection of astronauts from a rocket.

It was the last step before I could send a manned flight to the International Space Station. On Sunday January 19, SpaceX successfully simulated the emergency ejection of astronauts from a rocket moments after launch, according to a live broadcast of the test, the last major test before the shipment is expected in a few months from a NASA crew to the International Space Station. The test launch, with no one on board, started at 10:30 a.m. at the Kennedy space center in Florida with the takeoff of a Falcon 9 rocket, at the top of which the new SpaceX capsule, Crew Dragon, was fixed. The rocket was programmed as if it were to launch the spacecraft into orbit.

One minute and 24 seconds after takeoff, at an altitude of approximately 19 kilometers above the Atlantic and while the rocket was traveling at more than 1,500 km / h, an abandonment sequence was triggered to simulate a anomaly: the capsule ignited its powerful SuperDraco thrusters to eject from the rocket and distance itself from it as quickly as possible. In a manned mission, the maneuver would save the astronauts strapped inside Dragon, if the rocket ever had a problem or followed a bad trajectory.

Shortly after the sudden separation, the rocket disintegrated into a large ball of fire, which SpaceX had warned of. Crew Dragon continued, alone, its course towards the sky until about 40 km of altitude, before falling naturally towards the Atlantic Ocean. Then, the four large parachutes of the capsule opened to slow the fall and the ditching in the Atlantic, where rescue teams had been pre-positioned. Nine minutes after takeoff, Crew Dragon landed, apparently without damage. Analysis of the capsule and the flight data will confirm whether everything went well, and whether the vehicle is considered reliable for placing astronauts there. A press conference will take place Sunday at 11:30 a.m. (4:30 p.m. GMT) with officials from NASA and SpaceX.

Two American astronauts for a flight in March

The seemingly normal course of this perilous test is great news for SpaceX and for NASA, which urgently needs to certify a vehicle to transport its astronauts to the ISS this year. Since 2011, the United States has been obliged to have its astronauts travel on the Russian Soyuz rockets, the only ones to have this capacity since the retirement of the American shuttles. NASA signed a similar contract with Boeing, which developed the Starliner capsule.

In March 2019, SpaceX had made a one-week empty round trip to the ISS with Crew Dragon. In April, a ground test of the SuperDraco propellants had caused an explosion, but SpaceX and Nasa claim to have solved the problem after investigation. Boeing was to perform the same mission to the ISS in December, but an orbit error led to shortening the mission and bringing back Starliner two days after launch, a setback for the aerospace giant. The first manned flight of Crew Dragon will have as passengers American astronauts Doug Hurley and Bob Behnken. If all goes well, this mission will take place at the earliest in early March, said Kathy Lueders, head of NASA's commercial flight program on Friday.