What is the mission of NASA's TESS satellite?

Looking for exoplanets! TESS satellite will use transit method to observe planets near distant bright stars. Because the brightness of the star is very bright, only through the slight change of the brightness of the transit method can the planets near the star be detected. It can also be said that it is indirectly looking for extraterrestrial life. This article will give you a brief introduction to its tasks.

Brief introduction of transit exoplanet survey satellite

The transit exoplanet survey satellite (TESS) is a space telescope in NASA's Explorer program, which aims to search for exoplanets through transit, and its area is about 400 times that of the original Kepler mission. April, 2065438 18 was launched with Falcon 9 rocket. During its main mission, it is expected that more than 20,000 exoplanets will be discovered, compared with about 3,800 when it was launched. Tess's first Zhang Guangzhao image was taken on August 7th, 20 18 and released to the public on September 7th, 20 18.

Tess-The first optical photo (2065438+August 7th, 2008), photographed by NASA/MIT/Tess.

TESS's first mission is to observe the brightest star region near the earth for two years in order to search for exoplanets by transit method. TESS satellite uses a series of wide-field cameras to measure 85% of the sky. With the help of TESS, we can also study the mass, size, density and orbit of a large group of asteroids, including samples of rocky (terrestrial) planets in the habitable area of their main stars. Will Tess provide James? The Webb Space Telescope and other future space or ground telescopes are the targets for further observation. In the past, ground-based telescopes mainly observed huge and obvious exoplanets, and now our TESS will find a large number of asteroids near the stars. TESS will record the brightest main sequence star recently, and the main sequence star will have the transit of exoplanets, which is the most beneficial goal for detailed research.

TESS adopts a novel high elliptical orbit with apogee near the moon and perigee at 108000 km, which will be higher than the orbit of geosynchronous satellite. TESS will orbit the earth twice during its orbit around the moon, forming a 2: 1*** vibration orbit with the moon. It is predicted that this orbit will remain stable for at least 10 years.

Overview of the mission of the transit exoplanet survey satellite

TESS aims to measure exoplanets for the first time through the transit method of space-borne survey. It is equipped with four wide-angle telescopes and related CCD detectors. Scientific data will be transmitted to the earth every two weeks. In addition, a full-frame image with an effective exposure time of 2 hours will be transmitted, enabling scientists to search for unexpected transient phenomena, such as the optical counterpart of gamma ray bursts. TESS will also use the visiting researcher program to allow scientists from other organizations to use TESS data for their own research. In addition, 20,000 celestial bodies can be observed.

TESS's two-year all-day observation will focus on nearby G, K and M stars whose apparent magnitude ratio is 12 (equal). TESS will observe about 500,000 stars, including 1 1,000 red dwarfs that are closest to the earth across the whole sky, and the area will be 400 times that of Kepler's mission. It is estimated that TESS will discover more than 20,000 exoplanets, including 500 to 1000 planets with the same size as the earth and a super earth larger than the earth. Among these discoveries, it is estimated that 20 super-earths may be located in the orbits of habitable areas around stars. Most exoplanets are about 30 to 300 light-years away.

The survey is divided into 26 observation areas, each with a range of 24 degrees? 96 degrees, overlapping with the sector of the ecliptic pole, so as to have higher sensitivity to exoplanets with smaller regions and longer periods on the celestial sphere. The spacecraft will observe each sector with two orbital periods of 13.7 days. In the first year of its operation, it will draw the sky in the southern hemisphere, and in the second year, it will draw the sky in the northern hemisphere. The camera actually takes an image every 2 seconds, but the amount of data of all original images is much larger than that stored or downloaded. This means that in two years, TESS will continue to investigate 85% of the sky within 27 days, some of which will span multiple observations. Design the sky survey method, so that the area basically continuously measured throughout the year (35 1 observation day) accounts for about 5% of the whole sky, including the area near the ecliptic pole. It can be celebrated with JWST at any time of the year.

The TESS team also plans to use the observation frequency of 30 minutes to complete the shooting of full-frame images, which is based on imposing the Nyquist frequency limit, which may be a problem for the astronomical seismology of stars. Astrobiology is a science that studies the internal structure of stars by interpreting their frequency spectrum. Different oscillation modes penetrate into different depths inside the star. Kepler mission and Plato Observatory are also used in the study of astroseismology.

Test images taken before the start of scientific experiments. The image is centered on Centauri. You can see the edge of the coal pocket nebula in the upper right corner, and the bright star in the lower left is Centauri? . Photo: NASA/MIT/Tess