NASA's Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star's habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA's Spitzer Space Telescope and have modeled the planet's potential environments to help inform future observations. TOI 700 is a small, cool M dwarf star located just over 100 light-years away in the southern constellation Dorado. It's roughly 40 of the Sun's mass and size and about half its surface temperature. The star appears in 11 of the 13 sectors TESS observed during the mission's first year, and scientists caught multiple transits by its three planets. The innermost planet, called TOI 700 b, is almost exactly Earth-size, is probably rocky and completes an orbit every 10 days. The middle planet, TOI 700 c, is 2.6 times larger than Earth -- between the sizes of Earth and Neptune -- orbits every 16 days and is likely a gas-dominated world. TOI 700 d, the outermost known planet in the system and the only one in the habitable zone, measures 20 larger than Earth, orbits every 37 days and receives from its star 86% of the energy that the Sun provides to Earth. All of the planets are thought to be tidally locked to their star, which means they rotate once per orbit so that one side is constantly bathed in daylight. The Spitzer data increased scientists' confidence that TOI 700 d is a real planet and sharpened their measurements of its orbital period by 56% and its size by 38%. It also ruled out other possible astrophysical causes of the transit signal, such as the presence of a smaller, dimmer companion star in the system. While the exact conditions on TOI 700 d are unknown, scientists used current information, like the planet's size and the type of star it orbits, and modeled 20 potential environments for TOI 700 d to gauge if any version would result in surface temperatures and pressures suitable for habitability. One simulation included an ocean-covered TOI 700 d with a dense, carbon-dioxide-dominated atmosphere similar to what scientists suspect surrounded Mars when it was young. The model atmosphere contains a deep layer of clouds on the star-facing side. Another model depicts TOI 700 d as a cloudless, all-land version of modern Earth, where winds flow away from the night side of the planet and converge on the point directly facing the star.

Astronomers using NASA's Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star's habitable zone. That’s crucial because it may mean the planet, called TOI 700 d, has liquid water on its surface. It also appears to have one side of the planet in eternal sunshine and the other in a never-ending night. What and where is planet TOI 700 d? It’s orbiting a star called TOI 700, a cool “M dwarf” star about 100 light-years away in the southern constellation of Dorado, the dolphinfish. About 40% of the Sun’s mass and size, and about half its surface temperature, TOI 700 is bright, nearby, and shows no sign of harmful “stellar flares.” That means that any planets in orbit don’t get frequent blasts of deadly radiation that would almost certainly make life impossible. However, the TOI 700 star system is unlike the solar system in that all three planets detected so far are thought to be tidally locked to their star. That means they show only one face to the star—as the moon does to Earth—but it therefore means that only one side ever gets daylight. TESS’s first Earth-size planet in its star's habitable zone is nevertheless destined to be a very weird world indeed.

Youtube channel https://www.youtube.com/user/cxcpub/featured Description Since its launch on July 23, 1999, the Chandra X-ray Observatory has been NASA's flagship mission for X-ray astronomy, taking its place in the fleet of "Great Observatories." We hope you’ll contribute to this interactive forum and to our ongoing conversation about the work we do. On-topic discussion is encouraged. We ask that you express yourself in a civil manner and treat other users with respect. We will monitor and may remove posts consistent with the Smithsonian terms of use, as described at http://si.edu/Termsofuse#user-gen The Smithsonian may archive materials posted on this website pursuant to its document retention policies. By posting content, you are giving the Smithsonian and those authorized by the Smithsonian permission to use or modify it for any educational, promotional, or other standard museum purpose, in media of all kinds whether now known or later developed.

The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the space shuttle Columbia during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit, and its mission is ongoing as of 2019. Chandra is one of the Great Observatories, along with the Hubble Space Telescope, Compton Gamma Ray Observatory (1991-2000), and the Spitzer Space Telescope. The telescope is named after the Nobel Prize-winning Indian-American astrophysicist Subrahmanyan Chandrasekhar. Its mission is similar to that of ESA's XMM-Newton spacecraft, also launched in 1999 but the two telescopes have different design foci; Chandra has much higher angular resolution.

It’s 2618 and humans are extinct. Four aliens travel to Earth to visit the museum of humanity. There they find the story of the last heroes of humanity, setting out to find help. Welcome to Earth is a short science fiction film filmed in the Netherlands. It was made with a large group of both professional and amateur filmmakers. To bring the world to life it was filmed on both unique locations and inside sets build specifically for this film. It contains designs in both props and costumes that are specifically created for this film.