Beijing time on November 28, extraterrestrial satellites refer to satellites that orbit certain planets outside the solar system, called "outer solar planets". Since 2009, the National Aeronautics and Space Administration (NASA) Kepler and the Satellite Transit Excavator (TESS) mission have found nearly 4,000 exoplanets, but astronomers only have one satellite outside the aircraft. Explained, and still not sure if it's a satellite.
The Kepler-1625b and satellite exoplane that might be estimated are comparable in size to Neptune. The researchers say that potential satellites and other similar space satellites might even have their own satellites.
In October 2018, David Kipping, an astronomer at Columbia University, and his postgraduate student, Alex Teachey, first reported this in the journal Science Advances. Potential space satellite.
Using the NASA Hubble Space Telescope, the two researchers analyzed observations when the Kepler-1625b spacecraft (Kepler-1625b) flew over the star. This is a planet similar in size to Jupiter, which blocks some of the light as it passes through a star. By analyzing starlight curves, planetary characteristics can be determined.
This observation method is called the transit method (occlusion). Astronomers have used this method to find thousands of exoplanets. However, the researchers found two surprises when observing the Kepler-1625b process flying above the stars. First, exoplanets fly over the star for 1.25 hours earlier than expected, indicating that something produces gravitational traction. Second, after the planet actually passes through a star, a very shallow gap appears on the light curve, which might indicate a satellite behind Kepler-1625b.
David Kiping said: "We have ruled out as many other possibilities as possible, such as detector errors, other planetary activities in the system, or other star activities, but we cannot find other hypotheses that can explain our hands. All the data in them."
This potential space satellite is about the same size as Neptune, about one third of Kepler-1625b. Satellite sizes are usually smaller than planets in orbit, so this book is quite extraordinary. As far as the current model of the formation of planet-satellite systems is concerned, such satellites must be very rare if they exist.
It is assumed that the quality of Kepler-1625b is about several times that of Jupiter, and the potential quality of the satellite may be only 1.5% of that. This mass ratio is similar to Earth and the Moon. On the Earth and the Moon system, the moon is thought to be formed by debris from rocky planet collisions. However, astronomers believe that Kepler 1625b and satellites may belong to gas planets and are not composed of rocks, so this space satellite might have been formed by a different process.
"We cannot rush to open a champagne celebration now," said Alex Titcher. "But everything looks interesting, interesting, and convincing."
Looking for life outside the satellite camera?
Some scientists claim that space satellites might be a "very habitable" world, which means they are a good place to live. This is because the satellite is not limited to using light energy from the parent star in the system, but can extract energy from other places, such as:
Reflected light. Reflected light or thermal radiation from nearby planets can provide long-term stable temperatures and can improve the evolution and reproduction of life.
Radioactive element. Radioactive elements such as uranium and thorium may exist deep in space rock formations with the same size of Earth, and over time these elements slowly decay and release heat to the surface of the satellite.
Tidal force. The gravitational pull of large extrasolar planets, such as the size of Jupiter or Saturn, may involve space satellites, creating tidal forces, similar to the tidal changes produced by the gravitational pull of the moon on Earth. When the extraterrestrial satellite surface is composed of rocks drawn by the gravitational pull of the extrasolar planet, the heat generated can reach the satellite surface.
There are about 175 satellites in the solar system that we enter. Many of these satellites have these characteristics, and two are also strong candidates for finding life in space: satellites Jupiter Europa (Meowe) and Saturn Enclades satellites (Luke).
Both satellites have a frozen surface coated with striated lines created by the planet's gravitational force, at temperatures not exceeding 128 degrees Celsius. However, just a few kilometers below the surface, there is a large liquid ocean containing liquid water that exceeds the total amount of water on earth. Where liquid water is present, there may be life.
Where are the other out-of-band satellites?
Some astronomers estimate that there may be many frozen satellites like that with the subsurface oceans in the Milky Way, which may be 100 to 1000 times larger than terrestrial planets, but are very difficult to find.
Kepler-1625b's parent star is about 8,000 light years from Earth, a distance that makes it a very small place on Earth, but with sophisticated detection techniques, scientists can see the planet's weak contours when passing in front of it. . For Kepler-1625b, this satellite is relatively easy to detect because of its large size. However, for satellites outside of other aircraft that have a size similar to Europa, which is equivalent to a quarter of Earth's volume, it is not easy to detect the "gap" signal left by them as they pass in front of the star. In the current technical conditions, this gap is too small to be clearly identified. Therefore, we need to be a little more patient to find more space satellites.