All articles tagged with #occultation
NASA’s Perseverance rover on Mars recorded a nine-image sequence in which Earth, a one-pixel dot 314 million kilometres away, passes behind Phobos, marking the first observation of Earth disappearing behind another world from the surface of a different planet; the event is presented as an annotated composite rather than a continuous video, highlighting careful geometry and timing.
Astronomers report Pluto’s nitrogen-rich atmosphere is starting to freeze out as it moves away from the Sun, with atmospheric pressure dropping about 16% between mid-2021 and 2023. Pluto’s surface runs at roughly -382°F while the upper atmosphere sits around -333°F, conditions that favor frost formation as the air cools. Observations of ten stellar occultations from 2017–2023 show haze in the lower atmosphere settling toward lower latitudes as pressure falls. The findings, led by Amanda Sickafoose, suggest the atmosphere will not be fully frozen by aphelion (2114) but should rebuild somewhat as Pluto travels back toward the Sun. The study was published July 31 in the Planetary Science Journal.
Pluto’s nitrogen‑rich atmosphere is starting to condense into frost as it drifts farther from the Sun on its 248‑year orbit. Surface temperatures are about -382°F (-230°C) and the upper atmosphere around -333°F (-203°C). Observations of ten stellar occultations from 2017–2023 show atmospheric pressure has declined ~16% since 2021 (likely haze settling to lower latitudes). NASA’s New Horizons had measured a baseline atmospheric pressure of about 10 microbars in 2015. Pluto’s aphelion will occur in 2114 at ~49 AU, and the atmosphere isn’t expected to be fully frozen by then; frost could sublimate and the atmosphere thicken again as Pluto heads back toward the Sun.
Astronomers using a 2024 stellar occultation detected signs of a thin, possibly temporary atmosphere around the tiny Kuiper Belt object 2002 XV93 (about 500 km across), challenging assumptions that such small bodies can hold an atmosphere. Any atmosphere would likely last under 1,000 years without replenishment, and no frozen surface gases were found by JWST to fuel it. Two scenarios are proposed: recent internal gas release or a comet impact. If confirmed, this would be the first atmosphere detected on a trans-Neptunian object other than Pluto, prompting further observations to understand the mechanism.
On June 17, a rare daytime occultation will have a thin crescent Moon pass in front of Venus across parts of North America in the mid‑afternoon; observers can use binoculars or a telescope but must avoid looking near the Sun, while the Moon serves as a guide to spot Venus (magnitude -4.0) in daylight; the event runs roughly 3:30–5:00 PM EDT, followed by evening views near the Beehive Cluster after sunset.
On June 17, 2026, the Moon will occult Venus in broad daylight for about 29 seconds, centered around 16:40 EDT, visible from northeastern South America, the Caribbean, the CONUS, northern Mexico and southern Canada before sunset; Venus will be about 38 degrees from the Sun and around magnitude -4, while the Moon is an 11 percent crescent. This is the first of three Venus occultations in 2026 (Sept 14 and Nov 7 are the others), with Mercury near greatest elongation the day before. Plan with IOTA timings or Stellarium to target local times and try daytime video capture, noting autofocus can be tricky.
Astronomers observed the small Kuiper Belt object 2002 XV93 (about 311 miles across) during a stellar occultation and found a very thin atmosphere, making it only the second TNO known to have one after Pluto. The atmosphere, five to ten million times thinner than Earth's, could result from cryovolcanic activity or a recent icy impact; its persistence or dissipation could help distinguish between these sources. Future James Webb Space Telescope observations may detect additional gases like methane or carbon monoxide.
A diminutive trans-Neptunian object known as (612533) 2002 XV93 (a ~500 km Pluto-like body in Neptune’s 2:3 resonance) has unexpectedly developed a thin atmosphere (exosphere). Its presence was inferred from a January 2024 stellar occultation observed by a Japan-led team; the exosphere is extremely tenuous, with surface pressures of 100–200 nanobars—5 to 10 million times thinner than Earth’s. The atmosphere could originate from a recent impact or from cryovolcanic outgassing, but either way it challenges the idea that only large bodies can sustain atmospheres. If it’s impact-driven, the gas would escape within ~1,000 years; if outgassing, the source is ongoing beneath the surface. JWST observations and density monitoring in coming years should help pinpoint the cause. The discovery was published May 4 in Nature Astronomy.
Astronomers detected a surprisingly thin atmosphere around 2002 XV93, a ~500-km plutino in the Kuiper belt, via a 2024 stellar occultation observed from Japan. The inferred atmosphere is about 100–200 nanobars—extremely tenuous and likely transient—suggesting replenishment from a recent impact or ongoing cryovolcanism. This challenges the notion that atmospheres only form on large bodies and shows that small distant objects can host detectable atmospheres, with the research published in Nature Astronomy.
Astronomers using stellar occultations found that (612533) 2002 XV93, a ~500-km trans-Neptunian object, has a thin, Pluto-like atmosphere, making it the first TNO with an atmosphere; the feature could be temporary or long-lasting, and further multi-site observations are planned to uncover its origin and evolution.
Astronomers observed a January 2024 stellar occultation by trans-Neptunian object (612533) 2002 XV93, seeing its background star fade and recover, which provides evidence for a very thin atmosphere around this Pluto-like distant world in the Kuiper Belt.
Space.com reports a 2:00 PM EDT (1800 GMT) livestream from The Virtual Telescope Project showing the waxing crescent Moon occulting the Pleiades (the Seven Sisters, Messier 45) on April 19; US viewers get a daytime occultation while Italian viewers can watch after sunset, with Earthshine illuminating the Moon’s dark edge as the pair pass about 445 light-years away.
Astronomers observed a sun-like star, J0705+0612, being occulted by a colossal 120‑million‑mile‑wide cloud of metal-rich gas and dust for about nine months. Using high‑resolution spectroscopy from Gemini South (GHOST) and other telescopes, they mapped the cloud’s three‑dimensional motions and chemical makeup (iron, calcium), finding it is bound to another object heavy enough to exert gravity—likely a massive planet or a low‑mass star. The team proposes the cloud formed from a collision between two orbiting bodies, creating a circumplanetary or circumsecondary disk. The discovery, published in The Astronomical Journal, offers a rare glimpse into dynamic, late‑stage planetary systems and how such large structures can persist in a system thought to be ~2 billion years old.
Astronomers observed a dynamic and evolving ring system forming around the centaur object Chiron in real time, providing insights into the formation and development of rings around small Solar System bodies, with ongoing changes suggesting a recent ejection of material and a transitional stage in ring system evolution.
The October 2025 new moon will coincide with the peak of the Orionid meteor shower and will occult the red star Antares for observers in South America and the Falklands, offering a rare celestial event alongside visible planets like Saturn, Jupiter, and Venus.