Study Findings: The Influence of Passing Field Stars on the Solar System’s Dynamical Future

Posted on by onespaceman2000
Credit: Image by Yol Gezer from Pixabay.

Icarus abstract of the study findings:

The long-term dynamical future of the Sun’s planets has been simulated and statistically analyzed in great detail, but most prior work considers the solar system as completely isolated, neglecting the potential influence of field star passages. To understand the dynamical significance of field star encounters, we simulate several thousand realizations of the modern solar system in the presence of passing field stars for 5 Gyrs. We find that the impulse gradient of the strongest stellar encounter largely determines the net dynamical effect of field stars. Because the expected strength of such an encounter is uncertain by multiple orders of magnitude, the possible significance of field stars can be large. Our simulations indicate that isolated models of the solar system can underestimate the degree of our giant planets’ future secular orbital changes by over an order of magnitude. In addition, our planets and Pluto are significantly less stable than previously thought. Field stars transform Pluto from a completely stable object over 5 Gyrs to one with a ∼5% instability probability. Furthermore, field stars increase the odds of Mercury’s instability by ∼50%–80%. We also find a ∼0.3% chance that Mars will be lost through collision or ejection and a ∼0.2% probability that Earth will be involved in a planetary collision or ejected. Compared to previously studied instabilities in isolated solar systems models, those induced by field stars are much more likely to involve the loss of multiple planets. In addition, they typically happen sooner in our solar system’s future, making field star passages the most likely cause of instability for the next 4–4.5 Gyrs.

Citation: Kaib, Nathan A. and Raymond, Sean N., The influence of passing field stars on the solar system’s dynamical future, Icarus (2005).

https://doi.org/10.1016/j.icarus.2025.116632

Study-related stories:

The New York Times

Science News

Planetary Science Institute

NASA Advisory Groups Share Concerns About Budget Cuts

Posted on by onespaceman2000

NASA Watch published a letter from representatives of the agency’s advisory groups, including:

The letter highlights the importance of science initiatives at NASA at a time when drastic budget cuts are being considered, and quotes Carl Sagan:

Cutting off fundamental, curiosity-driven science is like eating the seed corn. We may have a little more to eat next winter but what will we plant so we and our children will have enough to get through the winters to come?

It’s a much needed yet bold approach at this time when the White House is eliminating all opposition to its wild cuts and erratic attack on diversity. The White House is actively shutting down advisory committees through the federal government, including NASA.

We can only hope the public listens to the wiser voices from these advisory committees. Someday all of this will need to be rebuilt, including our space program, but for now we need to save as much as we can from random cuts from parties that do not seem to understand the important role of science in our economy and our future.

NASA 2025 Calendar and More

Posted on by onespaceman2000
Credit: NASA

If you are looking for a colorful calendar or simply some amazing images and art, you cannot go wrong downloading NASA’s 2025 calendar. For example, the graphics shown above and below are just two examples of the pages you can find in this 32-page calendar. It shows the number of NASA-led or supported space missions throughout our solar system. It is a numbing number of missions.

Have you heard of ESCAPADE mission, which stands for the Escape and Plasma Acceleration and Dynamics Explorers? Checking the NASA site, I learned that this mission was a dual-spacecraft mission to study ion and sputtered escape from Mars, and it was supposed to be launched this week but it was put back on the shelf. Here is more on the mission:

The planned launch on the Blue Origin New Glenn booster from Cape Canaveral, originally scheduled for October 13, 2024, has been delayed indefinitely. The science goals of the mission are to: understand the processes controlling the structure of Mars’ hybrid magnetosphere and how it guides ion flows; understand how energy and momentum are transported from the solar wind through Mars’ magnetosphere; and understand the processes controlling the flow of energy and matter into and out of the collisional atmosphere. EscaPADE is part of the NASA Small Innovative Missions for Planetary Exploration (SIMPLEx) program.

I am learning about it just in time to find out it is going nowhere for the moment.

Of course, there are many more on the list that you can look up for yourself. For instance, Google the European Space Agency’s BepiColombo.

Image (Credit): Second part of the Science Fleet – Operating & Future Missions. (NASA)

Space Stories: Launch of the Euclid Space Telescope, Mercury Flyby, and a Super Hot Brown Dwarf

Posted on by onespaceman2000
Image (Credit): Artist’s rendering of the ESA’s Euclid Space Telescope. (ESA, CC BY-SA 3.0 IGO)

Here are some recent stories of interest.

—NASA/JPL: “NASA to Provide Coverage for Launch of ESA ‘Dark Universe’ Mission“

The ESA (European Space Agency) and SpaceX are targeting no earlier than 11:11 a.m. EDT (8:11 a.m. PDT) Saturday, July 1, to launch the Euclid spacecraft. Euclid is an ESA mission with contributions from NASA that will shed light on the nature of dark matter and dark energy, two of the biggest modern mysteries about the universe.

—Sky&Telescope: “BepiColombo Mission Makes Third Mercury Flyby“

An intrepid space mission had another brief glimpse of its final destination this week, as the European Space Agency’s BepiColombo flew past Mercury for a third time. The team confirms that the spacecraft is in good health post flyby, and that all instruments performed as planned. “Everything went very smoothly with the flyby and the images from the monitoring cameras taken during the close-approach phase of the flyby have been transmitted to the ground,” said Ignacio Clerigo (ESA) in a recent press release. “While the next Mercury flyby isn’t until September 2024, there are still challenges to tackle in the intervening time.”

—Phys.org: “Discovery of a Brown Dwarf Hotter than the Sun“

An international team of astronomers has discovered a planet-like object that is hotter than the sun. Their report has been accepted for publication in the journal Nature Astronomy and is currently available on the arXiv pre-print server. Brown dwarfs are sometimes called failed stars and do not qualify for the category of either a planet or a star. In this new effort, the researchers have identified one that orbits a star so closely that its temperature is hotter than our sun.

Have You Heard of Super-Mercuries?

Posted on by onespaceman2000
Image (Credit): Surface of Mercury captured by NASA’s MESSENGER spacecraft.(NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

I often here of super-Earths among the spotted expolanets, but super-Mercuries? They are less common, with only eight spotted to date, including two recently found around exoplanet using the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) spectrograph on the European Southern Observatory’s Very Large Telescope in Chile. The two super-Mercuries were spotted in the star system HD 23472 along with two super-Earths.

Researcher researcher Susana Barros with the Astrofísica e Ciências do Espaço’s, who led the team that found the new super-Mercuries, stated:

For the first time we have discovered a system with two super-mercuries. This allows us to obtain clues about how these planets were formed, which could help us exclude some possibilities. For example, if an  impact large enough to create a Super-Mercury is already very unlikely, two giant impacts in the same system seems very improbable. We still don’t know how these planets are formed but it appears to be connected to the composition of the parent star. This new system can help us find out.

Much of the exoplanet talk to date has been about super-Earths and mini-Neptunes, so it is nice to see a super-Mercury thrown into the mix. With the exoplanet search is still in its early days, expect more local planet terminology to be added to the discussion.

For more on the super-Mercury story, go here.