Multiple Choice: What is the average distance between the asteroids located in the asteroid belt between Mars and Jupiter?
A. 4,000 miles
B. 50,000 miles
C. 600,000 miles
D. 1.1 million miles
Take a guess and then check your answer by going to the “Astronomy Question Answer Sheet” page.
Here are some recent space-related stories of interest.
—Time: “China’s Imperiled Astronauts Illustrate the Dangers of Space Debris“
No trip to space can be counted a success unless you make it safely back to Earth…And it’s a lesson that was learned anew this week by the taikonauts—Chinese astronauts—Chen Dong, Chen Zhongrui, and Wang Jie. The trio arrived at China’s Tiangong Space Station aboard their Shenzhou-20 spacecraft on April 24, and were set to come home on Nov. 5, handing the keys to the station over to the three-person crew of Shenzhou-21, who arrived on Oct. 31. But that was not to be. Not long before Shenzhou-20 was set to carry the three home it was struck by a piece of space debris, leaving cracks in one of its windows. That can be deadly in a spacecraft that is supposed to remain airtight both in the vacuum of space and in the steadily thickening atmosphere as it returns to Earth.
—Yahoo News: “Russian Cosmonauts Take Shelter on International Space Station During Severe Solar Storm“
A powerful geomagnetic storm that dazzled skywatchers across the Northern Hemisphere earlier this month also affected life aboard the International Space Station (ISS). During the Nov. 11-12 solar storm, Russian cosmonauts temporarily relocated their sleeping quarters as a precaution against increased radiation exposure, NASA confirmed.
—Space News: “Dream Chaser Completes Key Tests Ahead of First Flight“
Sierra Space has completed key testing milestones for its Dream Chaser vehicle as the company explores both civil and national security missions for the spaceplane. The company announced Nov. 13 that the first Dream Chaser vehicle, Tenacity, completed electromagnetic interference and compatibility testing at NASA’s Kennedy Space Center...While Sierra Space is emphasizing national security uses, the company is keeping open the option of using Dream Chaser to support the ISS or future commercial space stations, known as commercial low Earth orbit destinations, or CLDs.
The Astrophysical Journal Letters abstract of the study findings:
The evolution and structure of sub-Neptunes may be strongly influenced by interactions between the outer gaseous envelope of the planet and a surface magma ocean. However, given the wide variety of permissible interior structures of these planets, it is unclear whether conditions at the envelope–mantle boundary will always permit a molten silicate layer or whether some sub-Neptunes might instead host a solid silicate surface. In this work, we use internal structure modeling to perform an extensive exploration of surface conditions within the sub-Neptune population across a range of bulk and atmospheric parameters. We find that a significant portion of the population may lack present-day magma oceans. In particular, planets with a high atmospheric mean molecular weight and large envelope mass fraction are likely to instead have a solid silicate surface, since the pressure at the envelope–mantle boundary is high enough that the silicates will be in solid postperovskite phase. This result is particularly relevant given recent inferences of high-mean molecular weight atmospheres from JWST observations of several sub-Neptunes. We apply this approach to a number of sub-Neptunes with existing or upcoming JWST observations and find that in almost all cases, a range of solutions exist that do not possess a present-day magma ocean. Our analysis provides critical context for interpreting sub-Neptunes and their atmospheres.
Citation: Bodie Breza et al. Not all sub-Neptune exoplanets have magma oceans. ApJL 993 L46 (2025).
https://doi.org/10.3847/2041-8213/ae0c07
Study-related stories:
Universe Today – “It Looks Like All Mini-Neptunes Aren’t Magma Oceans After All”
University of Chicago – “New Study Revises Our Picture of the Most Common Planets in the Galaxy”
Space.com – “Is Our Dream of Finding Ocean-Covered Exoplanets Drying Up?”
“…actions taken during the last nine months threaten the workers at Goddard and their ability to lead the world in this science and exploration. Between unnecessary voluntary separations, deferred resignations, reductions in force, and other pressure, thousands of civil servants and contractors are no longer working at GSFC. Other countries with space programs from our political allies to our adversaries have been recruiting our top scientists and researchers with massive salaries, research budgets, and the promise of stability. Where the US has considered stepping back, China has made clear they are eager to step in. We can and must re-invest in the people and centers that make America the global space leader and that starts with Goddard.”
-Statement in a November 13th letter from Maryland’s Senators and Representatives to NASA’s Acting Administrator Sean Duffy regarding recent cuts at NASA’s Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. The letter included four questions to be answered by November 17th.
This is really getting ridiculous. With the reopening of the federal government, the public has moved onto a new topic, and once again it is sex offender Jeffrey Epstein and his emails. However, this time it touches upon an popular cosmologist who wrote a book about Star Trek.
According to recent news stories, cosmologist Lawrence Krauss, author of The Physics of Star Trek, wrote to Mr. Epstein back in 2018 asking for ways to handle sexual harassment complaints against him. Mr. Epstein was a financial supporter of a program run by Dr. Krauss at Arizona State University (ASU). That same year, Dr. Krauss announced his retirement as professor at ASU while dealing with such charges. Dr. Krauss was also a contributor to Scientific American magazine and sat on Scientific American’s board of advisers, but was removed from the board in 2018 for reasons related to allegations of sexual misconduct.
As has been reported endlessly, Mr. Epstein engaged with a very large group of individuals, so Dr. Krauss is not alone. Still, it is not something you want on your resume.
You can still find Dr. Krauss sharing ideas on his podcast, The Origins Podcast with Lawrence Krauss, as well as his substack, Critical Mass. Whether this Epstein topic comes up on either the podcast or substack is anyone’s guess.
Dr. Krauss once stated:
For, after all, in science one achieves the greatest impact (and often the greatest headlines) not by going along with the herd, but by bucking against it.
I don’t believe he was talking about these latest headlines.
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