Darwin was a suggested ESA Cornerstone mission which would have involved a constellation of four to nine spacecraft designed to directly detect Earth-like planets orbiting nearby stars and search for evidence of life on these planets. The most recent design envisaged three free-flying space telescopes, each three to four metres in diameter, flying in formation as an astronomical interferometer. These telescopes were to redirect light from distant stars and planets to a fourth spacecraft, which would have contained the beam combiner, spectrometers, and cameras for the interferometer array, and which would have also acted as a communications hub. There was also an earlier design, called the "Robin Laurance configuration," which included six 1.5 metre telescopes, a beam combiner spacecraft, and a separate power and communications spacecraft.
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light through air decreasing with increased density. Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages. Turbulent air can make distant objects appear to twinkle or shimmer. The term also applies to the refraction of sound. Atmospheric refraction is considered in measuring the position of both celestial and terrestrial objects.
Gravitational microlensing is an astronomical phenomenon caused by the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers can only detect bright objects that emit much light (stars) or large objects that block background light. These objects make up only a minor portion of the mass of a galaxy. Microlensing allows the study of objects that emit little or no light.
The Calar Alto Observatory is an astronomical observatory located in Almería province in Spain on Calar Alto, a 2,168-meter-high (7,113 ft) mountain in the Sierra de Los Filabres subrange of the Sierra Nevada.
The New Worlds Mission is a proposed project comprising a large occulter flying in formation with a space telescope designed to block the light of nearby stars in order to observe their orbiting exoplanets. The observations could be taken with an existing space telescope or a dedicated visible light optical telescope optimally designed for the task of finding exoplanets. A preliminary research project was funded from 2005 through 2008 by NASA Institute for Advanced Concepts (NIAC) and headed by Webster Cash of the University of Colorado at Boulder in conjunction with Ball Aerospace & Technologies Corp., Northrop Grumman, Southwest Research Institute and others. Since 2010 the project has been looking for additional financing from NASA and other sources in the amount of roughly US$3 billion including its own four-meter telescope. If financed and launched, it would operate for five years.
OGLE-2005-BLG-390Lb is a super-Earth exoplanet orbiting OGLE-2005-BLG-390L, a star 21,500 ± 3,300 light-years from Earth near the center of the Milky Way, making it one of the most distant planets known. On January 25, 2006, Probing Lensing Anomalies NETwork/Robotic Telescope Network (PLANET/Robonet), Optical Gravitational Lensing Experiment (OGLE), and Microlensing Observations in Astrophysics (MOA) made a joint announcement of the discovery. The planet does not appear to meet conditions presumed necessary to support life.
PLAnetary Transits and Oscillations of stars (PLATO) is a space telescope under development by the European Space Agency for launch in 2026. The mission goals are to search for planetary transits across up to one million stars, and to discover and characterize rocky extrasolar planets around yellow dwarf stars, subgiant stars, and red dwarf stars. The emphasis of the mission is on Earth-like planets in the habitable zone around Sun-like stars where water can exist in a liquid state. It is the third medium-class mission in ESA's Cosmic Vision programme and is named after the influential Greek philosopher Plato. A secondary objective of the mission is to study stellar oscillations or seismic activity in stars to measure stellar masses and evolution and enable the precise characterization of the planet host star, including its age.
Kepler-62e is a super-Earth exoplanet discovered orbiting within the habitable zone of Kepler-62, the second outermost of five such planets discovered by NASA's Kepler spacecraft. Kepler-62e is located about 990 light-years from Earth in the constellation of Lyra. The exoplanet was found using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-62e may be a terrestrial or ocean-covered planet; it lies in the inner part of its host star's habitable zone.
Kepler-186f is an Earth-sized exoplanet orbiting within the habitable zone of the red dwarf star Kepler-186, the outermost of five such planets discovered around the star by NASA's Kepler space telescope. It is located about 580 light-years from Earth in the constellation of Cygnus.
Kepler-442b is a confirmed near-Earth-sized exoplanet, likely rocky, orbiting within the habitable zone of the K-type main-sequence star Kepler-442, about 1,206 light-years (370 pc) from Earth in the constellation of Lyra.
Kepler-452b is a super-Earth exoplanet orbiting within the inner edge of the habitable zone of the sun-like star Kepler-452 and is the only planet in the system discovered by the Kepler space telescope. It is located about 1,400 light-years (430 pc) from Earth in the constellation of Cygnus.
Kepler-1229b is a confirmed super-Earth exoplanet, likely rocky, orbiting within the habitable zone of the red dwarf Kepler-1229, located about 870 light years from Earth in the constellation of Cygnus. It was discovered in 2016 by the Kepler space telescope. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.
The Large Ultraviolet Optical Infrared Surveyor, commonly known as LUVOIR, is a multi-wavelength space telescope concept being developed by NASA under the leadership of a Science and Technology Definition Team. It is one of four large astrophysics space mission concepts studied in preparation for the National Academy of Sciences 2020 Astronomy and Astrophysics Decadal Survey.
TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a rocky, close-to-Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1, located 40.7 light-years away from Earth in the constellation of Aquarius. Astronomers used the transit method to find the exoplanet, a method that measures the dimming of a star when a planet crosses in front of it.
The Habitable Exoplanet Observatory (HabEx) is a space telescope concept that would be optimized to search for and image Earth-size habitable exoplanets in the habitable zones of their stars, where liquid water can exist. HabEx would aim to understand how common terrestrial worlds beyond the Solar System may be and determine the range of their characteristics. It would be an optical, UV and infrared telescope that would also use spectrographs to study planetary atmospheres and eclipse starlight with either an internal coronagraph or an external starshade.
Origins Space Telescope (Origins) is a concept study for a far-infrared survey space telescope mission. A preliminary concept in pre-formulation, it was presented to the United States Decadal Survey in 2019 for a possible selection to NASA's large strategic science missions. Origins would provide an array of new tools for studying star formation and the energetics and physical state of the interstellar medium within the Milky Way using infrared radiation and new spectroscopic capabilities.
Ross 128 b is a confirmed Earth-sized exoplanet, likely rocky, that is orbiting near the inner edge of the habitable zone of the red dwarf star Ross 128, at a distance of around 11 light-years from Earth in the constellation of Virgo. The exoplanet was found using a decade's worth of radial velocity data using the European Southern Observatory's HARPS spectrograph at the La Silla Observatory in Chile. Ross 128 b is the nearest exoplanet around a quiet red dwarf, and is considered one of the best candidates for habitability. The planet is only 35% more massive than Earth, receives only 38% more starlight, and is expected to be a temperature suitable for liquid water to exist on the surface, if it has an atmosphere.
Large Interferometer For Exoplanets (LIFE) is a project started in 2017 to develop the science, technology and a roadmap for a space mission to detect and characterize the atmospheres of dozens of warm, terrestrial extrasolar planets. The current plan is for a nulling interferometer operating in the mid-infrared.
The Extreme-ultraviolet Stellar Characterization for Atmospheric Physics and Evolution (ESCAPE) mission aims to find environments beyond Earth's solar system that might host planets with thick atmospheres to support life.
