SETI Institute

PRESS RELEASE: https://buff.ly/473FqGg Meteor Showers Shed Light on Where Comets Formed in the Early Solar System An international team of 45 researchers studying meteor showers has found that not all comets crumble the same way when they approach the Sun. In a paper published in the journal Icarus this week, they ascribe the differences to the conditions in the protoplanetary disk where comets formed 4.5 billion years ago. “The meteoroids we see as meteors in the night sky are the size of small pebbles,” said lead author and SETI Institute and NASA Ames meteor astronomer Peter Jenniskens. “They are, in fact, the same size as the pebbles that collapsed into comets during the formation of our solar system.” As our solar system formed, tiny particles in the disk around the young Sun gradually grew larger until they became the size of small pebbles. “Once pebbles grow large enough to no longer travel along with the gas, they are destroyed by mutual collisions before they can grow much bigger,” said NASA Ames planetary scientist and co-author Paul Estrada. “Comets and primitive asteroids instead were formed when clouds of these pebbles locally collapsed into kilometer-sized and larger bodies.” Fast forward 4.5 billion years: when comets approach the Sun today, they crumble into smaller pieces called meteoroids. Those meteoroids co-orbit with the comet for a while and can later create meteor showers when they hit Earth’s atmosphere. “We hypothesized that comets crumble into the sizes of the pebbles they are made of,” said Jenniskens. “In that case, the size distribution and the physical and chemical properties of young meteoroid streams still contain information about the conditions in the protoplanetary disk during this collapse.” Jenniskens and his team of professional and amateur astronomers use special low-light video cameras in networks all over the world to track meteors in a NASA-sponsored project called “CAMS” – or Cameras for Allsky Meteor Surveillance (http://cams.seti.org). “These cameras measure the meteoroids’ paths, how high they are when they first light up, and how they slow down in Earth’s atmosphere,” said Jenniskens. “Specialized cameras measured the composition of some of these meteoroids.” The team studied 47 young meteor showers. Most are the crumbs of two types of comets: Jupiter-family comets from the Scattered Disk of the Kuiper Belt beyond Neptune and long-period comets from the Oort Cloud surrounding our solar system. Long-period comets move on much wider orbits than the Jupiter-family comets and are much more loosely held by the Sun’s gravity. IMAGE: Artist's illustration of planets emerging from the dense disk of gas and dust encircling young stars. CREDIT: NASA's Goddard Space Flight Center

https://buff.ly/3AYOjEO The planet, which is named TIC 393818343 b and resides about 300 light-years away from Earth, was confirmed by two networks of citizen scientists, the UNISTELLAR Network and NASA's Exoplanet Watch. The teams used their own telescopes to watch light from a nearby star dim. Such dimming is a tell-tale sign of an orbiting planet transiting between its star and our detectors on Earth. The first "transit" was detected by the UNISTELLAR group, which then predicted when the next one would occur and alerted NASA's Exoplanet Watch group to help watch the star during the predicted time, according to a NASA statement.

Big Picture Science Radio Show: Calling All Aliens (ENCORE) Are we alone in the universe? Is there other intelligence out there? COSMIC, the most ambitious SETI search yet, hopes to answer that. We hear updates on this novel signal detection project being conducted on the Very Large Array in the desert of New Mexico. Also, we chat with award-winning science fiction writer Ted Chiang about how he envisions making contact with aliens in his stories, including the one that was the basis for the movie Arrival. And find out why some scientists don’t want only to listen for signals, they want to deliberately transmit messages to aliens. Is that wise and, if we did it, what would we say? Listen here: https://buff.ly/3AON3Eo

#PPOD: JunoCam Captures Jupiter on 62nd Flyby This view of Jupiter was captured by the JunoCam instrument aboard NASA's Juno spacecraft during the mission's 62nd close flyby of the giant planet on June 13, 2024. Citizen scientist Jackie Branc made the image using raw JunoCam data. Credit: NASA/JPL-Caltech/SwRI/MSSS Image processing: Jackie Branc Sign up for our enews: https://buff.ly/4gcYGVJ

SETI Institute Achievements: Q2 2024 Activity Report At the SETI Institute, there are more than 100 of us leading humanity’s question to understand the origins and prevalence of life and intelligence in the universe and sharing that knowledge with the world. They are conducting world-class scientific research on Earth, the solar system and beyond. Our education programs are fostering the next generation of scientists, explorers, educators and storytellers, and focusing on creating impact on communities with less access to scientific and educational resources. And our outreach efforts reach millions of people with stories of discovery. VIEW FULL REPORT HERE:

#PPOD: Friday Funny Enjoy some humor as we head into a holiday weekend here in the U.S.! Text: NASA successfully hurled an object into an asteroid at 14,000 mph to see if it could be knocked off course. The James Webb telescope took a detailed image of the impact site. Credit: ???

https://buff.ly/3ASsgzz The search for extraterrestrial intelligence, or SETI, is about looking for artificial radio signals from alien worlds. Or it might mean searching for other sorts of technosignatures, other signs of past or present technologies. And, so far, the search has concentrated mainly on stars in our home galaxy, the Milky Way. But now a new initiative has carried the search for intelligent aliens to other galaxies. It’s the first search of its kind for alien intelligence, with 2,800 galaxies scanned. On August 26, 2024, the SETI Institute, the Berkeley SETI Research Center and the International Centre for Radio Astronomy Research announced their new extragalactic SETI search. They said they used the Murchison Widefield Array (MWA) in Western Australia to scan the galaxies. The researchers published a preprint version of their new paper on arXiv on August 19, 2024.

Book review: https://buff.ly/3AJEx9G This stimulating survey from Cabrol, director of the Carl Sagan Center at the SETI Institute, details how she and other scientists search the cosmos for extraterrestrial life. Cabrol offers insight into what kinds of planets are most likely to harbor life by outlining theories for how life emerged on Earth, with some scientists claiming that the first organisms developed from alternating periods of dryness and wetness around volcanic hot springs, while others believe that reactions among RNA molecules in ice constitute a more likely genesis.

#PPOD: Neptune Clouds Showing Vertical Relief This Voyager 2 high-resolution color image, taken two hours before the spacecraft's closest approach to Neptune, provides evidence of vertical relief in Neptune's bright cloud streaks. The sides of the clouds that face the Sun are brighter than the surrounding cloud deck because they are more directly exposed to sunlight. Shadows can be seen on the side opposite the Sun. Cloud heights appear to be of the order of 50 kilometers. Credit: NASA/JPL Sign up for our enews: https://buff.ly/3XnaIoa

When a star at its life's end explodes, a debris cloud expands away from the now-dead star. The debris forms intricate and amazing structures in the expanding cloud and can cause the formation of a variety of molecules. Using the James Webb Space Telescope, scientists have collected information regarding Cassiopeia A (Cas A), the youngest known supernova remnant in the Milky Way. The observations shed light on how molecules and dust form and are destroyed in the aftermath of an explosion. These results suggest that supernovae, like Cas A, are key sources of the dust observed in ancient galaxies. A recent paper highlights the findings of this work, including the temperatures measured and molecules formed. Deputy Director of the Carl Sagan Center Simon Steel chats with lead author Jeonghee Rho and co-authors Danny Milisavljevic and Ilse De Looze about the data collected and what it means for dust formation in the universe. Press release: https://lnkd.in/eNB8dddc Paper: https://lnkd.in/eRu94_ek