Planetary Science Institute

Friends and colleagues gathered to celebrate Alan Fischer’s more than 14 years as the Planetary Science Institute’s Public Information Officer and surprise him with a chocolate fountain. Fischer has written hundreds of press releases, thousands of weekly cover stories and connected journalists with PSI experts to share exciting research with the public and advance science literacy. He has grown and overseen the media team, captured images of countless events and wrangled content to complete over a decade’s-worth of annual reports. He has also asked PSI to indulge him in a chocolate fountain for at least 10 years. His wish finally came true at his celebration. Attendees enjoyed pizza and dipped an assortment of fruit, Oreos, Rice Krispy Treats, pretzels and Red Vines in three tiers of flowing chocolate. “Alan brought his deep experience as a news reporter with national connections to main stream media, and built up the PSI public information department essentially from scratch,” said PSI CEO Mark Sykes. “We are all deeply grateful for his clear communication of the accomplishments of our scientists and educators and extending global awareness of what we do as an Institute. He is also a good friend.” In thanks of his service, Fischer also recently had an asteroid named in his honor: (14333) Alanfischer. Fischer passed the torch to PSI’s next PIO, Mikayla Kelley, on Dec. 1, 2024 while he maintains an advisory role at the institute.

Scientist Spotlight: Henry Hsieh Hsieh led the team that determined a mysterious object in the main asteroid belt was actually a main-belt comet. ☄️ Read more about the discovery here: https://buff.ly/4eUbM8C

Happy Friday! The happy and handsome Jasper is this week's PSI Planetary Pet. Japer was the most affectionate Aussie ever and lived with PSI's Dianne Janis. #PSIplanetarypet #aussie #planetarypet

PSI in the News: PSI's Pamela Gay spoke with NowMedia TV's Greg Schaeffer about space exploration and citizen science. Watch the full episode here: https://buff.ly/4i9EZz6

PSI Wishes You a Happy Thanksgiving! Delicious image of Saturn courtesy of NASA's creative Cassini mission team. #saturn #cassini

#JunoCam: This shot of a moody Jupiter was processed by Katie Jolly CSUMB. Want to participate in citizen science and process JunoCam images? https://buff.ly/3YxKRud

A mysterious object discovered in the main asteroid belt in 2021 was determined to be a main-belt comet by Planetary Science Institute Senior Scientist Henry Hsieh, Scott Sheppard of the Carnegie Institution for Science and Audrey Thirouin of Lowell Observatory. Main-belt comets are icy objects found in the asteroid belt between Mars and Jupiter – rather than the cold outer Solar System where icy bodies are typically expected. They sport comet-like features, like tails extending away from the Sun or fuzzy clouds as the Sun’s heat vaporizes their ice. They were first discovered in 2006 at the University of Hawaii by Hsieh and his then-doctoral advisor, David Jewitt. Main-belt comets belong to a larger group of Solar System objects known as active asteroids, which look like comets, but have asteroid-like orbits in the warm inner Solar System. This larger group includes objects whose clouds and tails are made of ejected dust produced after an impact or as they quickly rotate, rather than just those that eject dust due to vaporized ice. Both main-belt comets and active asteroids in general are still relatively rare, but scientists are discovering them at a growing clip. Hsieh and his colleagues observed active asteroid 456P/PANSTARRS twice using the Magellan Baade Telescope and Lowell Discovery Telescope in October 2024 to establish its status as the 14th confirmed main-belt comet. They published their findings in Research Notes of the American Astronomical Society. “This object is not just an asteroid that experienced a one-off event that caused it to show activity one time, but is an inherently active, icy body similar to other comets from the outer Solar System,” Hsieh said. If 456P/PANSTARRS’s activity were due to something other than ice vaporization, then its tail would be expected to appear only once randomly, and not repeatedly appear when it was close to the Sun. An icy object, on the other hand, heats up every time it approaches the Sun, and the vaporized ice drags dust out along with it. When the object moves farther from the Sun and cools, the activity stops. Observations of repeated dust ejection activity during close approaches to the Sun are currently considered the best and most reliable way to identify main-belt comets. “There are still very few confirmed main-belt comets known,” Hsieh said. “We want to build up the population so we can get a clearer idea of what their broader properties are – such as their sizes, activity duration and distribution within the asteroid belt, for example – so that they can be better used to trace ice in the Solar System in general.” More PSI cover stories: https://buff.ly/3OihndS Images of 456P/PANSTARRS taken with the Magellan-Baade telescope in Chile on October 3, 2024, and the Lowell Discovery Telescope in Arizona on October 26, 2024, where the head, or nucleus, of the comet is at the center of each image, and the tail extends to the right. Credit: Hsieh et al.

Scientist Spotlight: Alex Patthoff Patthoff was part of the team that determined Uranus' moon Miranda likely harbored an ocean beneath its surface. Read about the discovery, and learn more about what inspired him to become a scientist, some of the most exciting times in his career, and more: https://buff.ly/3V4he1u

This week's PSI #PlanetaryPet is handsome Leopold. PSI's Liz Jensen says he joins her for morning coffee and he likes getting scratched behind his ears.... but he doesn't approve of playfulness!

PSI in the News From Sky & Telescope: A polar cap of carbon-dioxide ice may have provided the thermal blanket needed for rivers and a huge lake to form in the planet’s southern highlands.