“TESS, the Transiting Exoplanet Survey Satellite, is NASA’s newest exoplanet mission. Led by MIT, TESS will find thousands of new planets orbiting nearby stars. During its two year survey, TESS will watch a wide variety of stars, looking for signs of planets ranging from Earth-size to larger than Jupiter.
Each of TESS’s cameras has a 16.8-megapixel sensor covering a square 24 degrees wide — large enough to contain an entire constellation. TESS has four of these cameras arranged to view a long strip of the sky called an observation sector. TESS will watch each observation sector for about 27 days before rotating to the next. It will cover the southern sky in its first year, and then begin scanning the north.
TESS will study 85 percent of the sky — an area 350 times greater than what NASA’s Kepler mission first observed — making TESS the first exoplanet mission to survey nearly the entire sky. Because TESS’s observation sectors overlap, it will have an area near the pole under constant observation. This region is easily monitored by the James Webb Space Telescope, which allows the two missions to work together to first find, and then carefully study exoplanets.”
Music Credit: “Drive to Succeed” from Killer Tracks
“NASA’s Transiting Exoplanet Survey Satellite – TESS – will fly in an orbit that completes two circuits around Earth every time the Moon orbits once. This special orbit will allow TESS’s cameras to monitor each patch of sky continuously for nearly a month at a time. To get into this orbit, TESS will make a series of loops culminating in a lunar gravity assist, which will give it the final push it needs. TESS will reach its orbit about 60 days after launch.”
Music Credit: “Drive to Succeed” from Killer Tracks
“Scheduled to launch in the mid-2020s, the Wide Field Infrared Survey Telescope (WFIRST) will function as Hubble’s wide-eyed cousin. While just as sensitive as Hubble’s cameras, WFIRST’s 300-megapixel Wide Field Instrument will image a sky area 100 times larger. This means a single WFIRST image will hold the equivalent detail of 100 pictures from Hubble.
The mission’s wide field of view will allow it to generate a never-before-seen big picture of the universe, which will help astronomers explore some of the greatest mysteries of the cosmos, like why the expansion of the universe seems to be accelerating. Some scientists attribute the speed-up to dark energy, an unexplained pressure that makes up 68 percent of the total content of the cosmos.
The Wide Field Instrument will also allow WFIRST to measure the matter in hundreds of millions of distant galaxies through a phenomenon dictated by Einstein’s relativity theory. Massive objects like galaxies curve space-time in a way that bends light passing near them, creating a distorted, magnified view of far-off galaxies behind them. WFIRST will paint a broad picture of how matter is structured throughout the universe, allowing scientists to put the governing physics of its assembly to the ultimate test.
WFIRST can use this same light-bending phenomenon to study planets beyond our solar system, known as exoplanets. In a process called microlensing, a foreground star in our galaxy acts as the lens. When its motion randomly aligns with a distant background star, the lens magnifies, brightens and distorts the background star. WFIRST’s microlensing survey will monitor 100 million stars for hundreds of days and is expected to find about 2,500 planets, well targeted at rocky planets in and beyond the region where liquid water may exist.
These results will make WFIRST an ideal companion to missions like NASA’s Kepler and the upcoming Transiting Exoplanet Survey Satellite (TESS), which are designed to study larger planets orbiting closer to their host stars. Together, discoveries from these three missions will help complete the census of planets beyond our solar system. The combined data will also overlap in a critical area known as the habitable zone, the orbiting distance from a host star that would permit a planet’s surface to harbor liquid water — and potentially life.
By pioneering an array of innovative technologies, WFIRST will serve as a multipurpose mission, formulating a big picture of the universe and helping us answer some of the most profound questions in astrophysics, such as how the universe evolved into what we see today, its ultimate fate and whether we are alone. “
“ESA’s XMM-Newton has spotted surprising changes in the powerful streams of gas from two massive stars, suggesting that colliding stellar winds don’t behave as expected. Massive stars – several times larger than our Sun – lead turbulent lives, burning their nuclear fuel rapidly and pouring large amounts of material into their surroundings throughout their short but sparkling lives.
These fierce stellar winds can carry the equivalent of Earth’s mass in a month and travel at millions of kilometres per hour, so when two such winds collide they unleash enormous amounts of energy. The cosmic clash heats the gas to millions of degrees, making it shine brightly in X-rays.
Normally, colliding winds change little because neither do the stars nor their orbits. However, some massive stars behave dramatically. This is the case with HD 5980, a pairing of two huge stars each 60 times the mass of our Sun and only about 100 million kilometres apart – closer than we are to our star. One had a major outburst in 1994, reminiscent of the eruption that turned Eta Carinae into the second brightest star in the sky for about 18 years in the 19th century. While it is now too late to study Eta Carinae’s historic eruption, astronomers have been observing HD 5980 with X-ray telescopes to study the hot gas.”
“Astronomers using NASA’s Hubble Space Telescope have conducted the first spectroscopic survey of the Earth-sized planets (d, e, f, and g) within the habitable zone around the nearby star TRAPPIST-1. This study is a follow-up to Hubble observations made in May 2016 of the atmospheres of the inner TRAPPIST-1 planets b and c. Hubble reveals that at least three of the exoplanets (d, e, and f) do not seem to contain puffy, hydrogen-rich atmospheres similar to gaseous planets such as Neptune.
Additional observations are needed to determine the hydrogen content of the fourth planet’s (g) atmosphere. Hydrogen is a greenhouse gas, which smothers a planet orbiting close to its star, making it hot and inhospitable to life. The results, instead, favor more compact atmospheres like those of Earth, Venus, and Mars.
By not detecting the presence of a large abundance of hydrogen in the planets’ atmospheres, Hubble is helping to pave the way for NASA’s James Webb Space Telescope, scheduled to launch in 2019. Webb will probe deeper into the planetary atmospheres, searching for heavier gases such as carbon dioxide, methane, water, and oxygen. The presence of such elements could offer hints of whether life could be present, or if the planet were habitable.
“Hubble is doing the preliminary reconnaissance work so that astronomers using Webb know where to start,” said Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, co-leader of the Hubble study. “Eliminating one possible scenario for the makeup of these atmospheres allows the Webb telescope astronomers to plan their observation programs to look for other possible scenarios for the composition of these atmospheres.”
The planets orbit a red dwarf star that is much smaller and cooler than our Sun. The four alien worlds are members of a seven-planet system around TRAPPIST-1. All seven of the planetary orbits are closer to their host star than Mercury is to our Sun. Despite the planets’ close proximity to TRAPPIST-1, the star is so much cooler than our Sun that liquid water could exist on the planets’ surfaces.”
“The Transiting Exoplanet Survey Satellite (TESS) is the next step in the search for planets outside of our solar system, including those that could support life. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey 200,000 of the brightest stars near the sun to search for transiting exoplanets. The mission is scheduled to launch in 2018.”
Music credit: “Prototype” and “Trial” both from Killer Tracks
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