Space Stories: Volcanic Exoplanets, Medieval Star Maps, and Near-Earth Asteroids

Posted on by onespaceman2000
Image (Credit): The lava lake that sits atop Mount Nyiragongo in the Democratic Republic of Congo (Stocktrek Images / Richard Roscoe via Getty Images)

Here are some recent stories of interest.

—Universe.com: “Scientists Discover a New Way Exoplanets Could Make Oxygen; Unfortunately, it Doesn’t Require Life“

The researchers have found an abiotic source of oxygen that stems from sulphur dioxide. Sulphur is not rare in celestial bodies, and since volcanoes produce sulphur and pump it into the atmosphere, terrestrial volcanic exoplanets may have oxygen in their atmospheres. And life needn’t be involved.

—Nature.com: “First Known Map of Night Sky Found Hidden in Medieval Parchment“

A medieval parchment from a monastery in Egypt has yielded a surprising treasure. Hidden beneath Christian texts, scholars have discovered what seems to be part of the long-lost star catalogue of the astronomer Hipparchus — believed to be the earliest known attempt to map the entire sky.

—Phys.org: “30,000 Near-Earth Asteroids Discovered, and Numbers are Rising“

We have now discovered 30,039 near-Earth asteroids in the solar system—rocky bodies orbiting the sun on a path that brings them close to Earth’s orbit. The majority of these were discovered in the last decade, showing how our ability to detect potentially risky asteroids is rapidly improving.

Study Findings: Early Mars Habitability and Global Cooling by H2-based Methanogens

Posted on by onespaceman2000
Image (Credit): Image of present day Mars. (NASA)

Nature Astronomy abstract:

During the Noachian, Mars’ crust may have provided a favourable environment for microbial life. The porous brine-saturated regolith would have created a physical space sheltered from ultraviolet and cosmic radiation and provided a solvent, whereas the below-ground temperature and diffusion of a dense, reduced atmosphere may have supported simple microbial organisms that consumed H2 and CO2 as energy and carbon sources and produced methane as a waste. On Earth, hydrogenotrophic methanogenesis was among the earliest metabolisms, but its viability on early Mars has never been quantitatively evaluated. Here we present a probabilistic assessment of Mars’ Noachian habitability to H2-based methanogens and quantify their biological feedback on Mars’ atmosphere and climate. We find that subsurface habitability was very likely, and limited mainly by the extent of surface ice coverage. Biomass productivity could have been as high as in the early Earth’s ocean. However, the predicted atmospheric composition shift caused by methanogenesis would have triggered a global cooling event, ending potential early warm conditions, compromising surface habitability and forcing the biosphere deep into the Martian crust. Spatial projections of our predictions point to lowland sites at low-to-medium latitudes as good candidates to uncover traces of this early life at or near the surface.

Citation: Sauterey, B., Charnay, B., Affholder, A. et al. Early Mars habitability and global cooling by H2-based methanogens. Nat Astron (2022). https://doi.org/10.1038/s41550-022-01786-w

Study-related stories:

First Class Fun from the US Post Office

Posted on by onespaceman2000
Credit: U.S. Postal Service

While the U.S. currency remains pretty boring, at least U.S. postage stamps continually change and highlight various aspects of American society. Two of those themes are science fiction and space exploration, and you have a few options if you want to show your interest in these areas.

These stamps include:

  • Star Wars Droids (above);
  • Space Ranger Buzz Lightyear (below); and
  • James Webb Space Telescope (below).

I know, you hardly ever write letters and you have a bunch of those boring flag stamps. Well, this is your chance to show a little more color on that birthday or anniversary card. Save the flag stamps for the bills.

Be a kid again, if only for a few moments.

Credit: U.S. Postal Service
Credit: U.S. Postal Service

Television: Debating Putin’s Nukes

Posted on by onespaceman2000

Astrophysicist Neil deGrasse Tyson was a guest on HBO’s Real Time with Bill Maher last Friday. During the broadcast he discussed his new book, Starry Messenger: Cosmic Perspectives on Civilization, which I commented on in an earlier post.

The odd part of the discussion came when Mr. Tyson was trying to explain that hydrogen bombs are not as bad as atomic bombs because they give off less lethal radiation. Bill Maher had earlier expressed his concerns about Russia’s Putin using a nuclear weapon and was surprised to learn that a hydrogen bomb was less dangerous in terms of radiation. He asked about this again, but Mr. Tyson went onto a different topic about the power of conventional arms and never did get back to Mr. Maher’s main concern.

Sadly, Mr. Tyson missed a chance to inform the audience about the dangers of nuclear weapons, be they hydrogen or atomic. As I had noted in an earlier post about nuclear risks, scientists have found that even a limited nuclear exchange can do great damage to the world because of the soot it throws into the upper atmosphere. A Columbia Climate School study on this issue, “Even a Limited India-Pakistan Nuclear War Would Bring Global Famine, Says Study,” found that even 50 Hiroshima-size explosions, which are quite small by today’s standards, would “…launch some 5 million tons of soot toward the stratosphere.” This soot would “…cause production of the world’s four main cereal crops—maize, wheat, soybeans and rice—to plummet an average 11 percent over that period, with tapering effects lasting another five to 10 years.” The impact of famine would lead to the loss of countless lives around the world.

The real risk today is a nuclear winter, which Mr. Tyson never explained. Instead, the audience was left with the impression that a nuclear explosion is not all that serious. Apparently, he was more interested in sharing all of his knowledge about World War II than addressing the question on the table. Mr. Tyson is supposed to be a good science communicator, so he really needs to correct the record. This is no time to be sloppy about nuclear war.

Artemis I: If at First You Don’t Succeed…

Posted on by onespaceman2000

NASA is ready to try the uncrewed Artemis I mission again next month. The planned date is November 14, with November 16 and 19 as back up dates.

Should you need it, here is a quick summary of the Artemis I mission again:

Artemis I will be the first integrated flight test of NASA’s deep space exploration system: the Orion spacecraft, Space Launch System (SLS) rocket and the ground systems at Kennedy Space Center in Cape Canaveral, Florida. The first in a series of increasingly complex missions, Artemis I will be an uncrewed flight that will provide a foundation for human deep space exploration, and demonstrate our commitment and capability to extend human existence to the Moon and beyond. During this flight, the uncrewed Orion spacecraft will launch on the most powerful rocket in the world and travel thousands of miles beyond the Moon, farther than any spacecraft built for humans has ever flown, over the course of about a three-week mission. 

I am tired of crossing my fingers, so let’s just hope these launch dates work.

Image (Credit): Artemis I mission map. (NASA)