![Penalty incurred when phase is unknown, with polarimetry. The true phase set is α = (150◦, 120◦, 90◦, 60◦, 30◦, 5◦). Left: known-phase radius consequence, in which trial phases are fixed to the true set. Middle: unknown-phase radius consequence, in which trial phase tuples are marginalized over the sampled grid while the normalized I400 lightcurve shape is included with the intensive observables. Right: unknown-phase to known-phase penalty ratio. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Multiepoch.png?resize=1200%2C720&ssl=1)
[astro-ph.EP] Direct imaging measures how bright a planet appears in reflected starlight, but brightness alone cannot tell whether the planet is large and dark or small and bright. This radius-albedo […]
Habitable Worlds Observatory
Rocky Worlds DDT Workshop
Join us at STScI for the Rocky Worlds DDT Workshop Data Challenge Results & Rocky Worlds DDT Science, a community gathering focused on the science enabled by the Rocky Worlds […]
HWO2026 (Habitable Worlds Observatory)
HWO2026 is an international scientific conference bringing together researchers, engineers, industry, and experts to discuss recent advances, ongoing developments, and future perspectives related to HWO. The conference will provide a […]
Posted inExoplanets, -moons, -comets
Searching For Habitable Exoplanets With Relative Astrometry (SHERA). I. The Case For Searching For Planets In Binary Star Systems
[astro-ph.EP] Discovering Earth-like planets orbiting Sun-like stars was identified as a priority science goal of the Astronomy 2020 Decadal Survey.
![[LEFT]: Schematic of the star–planet–observer geometry defining the phase angle α, measured between the star–planet and planet–observer directions. The hemisphere of the planet facing the star is fully illuminated (gold) at all times, while the opposite hemisphere remains in shadow. The observer sees only the portion of the illuminated hemisphere that is visible at a given α, with full illumination visible only at α = 0◦. [RIGHT]: Illustration of planetary phases along an edge-on orbit, with the star at the center and the observer direction indicated below the orbit. Although the star-facing hemisphere remains illuminated throughout the orbit, the visible fraction of this hemisphere changes with phase angle. Full phase occurs at α = 0◦, quadrature at α = 90◦, and new phase at α = 180 , with gibbous and crescent phases spanning the intermediate ranges. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Impact.png?resize=1200%2C714&ssl=1)
Posted inAstronomy & Telescopes
The Impact of Planetary Phase Functions On Exo-Earth Detectability With EXOSIMS
[astro-ph.EP] The under-development NASA Habitable Worlds Observatory (HWO) aims to provide breakthroughs in exoplanet science, yet the most effective approaches to modeling the detection and characterization of potentially Earth-like worlds […]
![(a) The HWK4123 sensor has a standard ceramic land grid array (CGLA) package and measures 31.1 × 36.6 mm. The imaging pixel array is in the center of the sensor. (b) The PHOTRON system is shown outside the dewar. The HWK4123 mounts behind the black enclosure in the top-left corner. (c) The QUEST camera attaches to the output of an integrating sphere, and the sphere receives light from a monochromator. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Single-Photon.png?resize=1200%2C704&ssl=1)
Posted inAstronomy & Telescopes
Single-Photon Counting CMOS Detectors For The Habitable Worlds Observatory
[astro-ph.IM] The Habitable Worlds Observatory (HWO) is NASA’s current New Great Observatory concept. HWO will observe the universe to search for life beyond Earth. It will need unprecedented instrument stability […]
![Pollux optical layout. The exact sequence in the optical path of the retractable polarimeters and fiber link connections of the OPT and NIR is still to be discussed and what shown here is not representative of the final configuration. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Pollux.png?resize=1200%2C715&ssl=1)
Posted inExoplanets, -moons, -comets
Pollux: High-resolution Precision Spectroscopy And Polarimetry For The Habitable Worlds Observatory
[astro-ph.IM] Pollux is a high-resolution spectrograph and spectropolarimeter (R from 65000 to 100000) covering a spectral range from 100 nm to 1750 nm, proposed by a European consortium to equip […]
Posted inExoplanets, -moons, -comets
Detecting Habitable Exoplanet Atmospheres With LIFE, The Large Interferometer For Exoplanets
[astro-ph.IM] A key goal of astronomers with the next generation telescopes is to detect signs of life in exoplanet atmospheres. NASA’s next flagship is the Habitable Worlds Observatory (HWO).
Posted inAstronomy & Telescopes
NASA SMD ROSES-25 Amendment 68: New Opportunity: D.8 Habitable Worlds Observatory Precursor Science Investigations
[NASA]. The Habitable Worlds Observatory (HWO) is a large-aperture ultraviolet/visible/near-infrared observatory concept recommended by the National Academies of Science, Engineering, and Medicine decadal survey, “Pathways to Discovery in Astronomy and […]
Posted inExoplanets, -moons, -comets
Welcoming The Virtual Planetary Laboratory To Its New Home At The SETI Institute
[SETI Institute] The Virtual Planetary Laboratory (VPL), one of NASA’s flagship astrobiology research teams, has officially moved its institutional home to the SETI Institute. In 2026 the VPL will also […]