Over the past couple of decades, astronomers have discovered thousands of alien planets and solar systems. These worlds come in a wide variety of arrangements, many of which are quite different from what we see in our own solar system.
Some have giant planets that swing through the planetary systems in stretched-out, or “eccentric,” elliptical orbits, unlike the nearly circular orbits of planets like Jupiter and Saturn.
Astronomers think that many of these eccentric giant planets would act like “wrecking balls” in their planetary systems, disturbing the orbits of other, smaller planets. But that’s not always the case, according to a study published last week in The Astronomical Journal .
Quite a lot has been going on:
NASA's Planet-Hunting TESS Spacecraft Snaps Spectacular Panorama of the Milky Way | Space
NASA's planet-hunting spacecraft created a spectacular panorama of the southern sky that shows off our home galaxy, the Milky Way.
The panorama includes 208 images that the Transiting Exoplanet Survey Satellite (TESS) took during its first year of science operations, which wrapped up July 18. This sweep of the sky is a bit of a broader view than usual for the mission, which is optimized to look at small planets as they pass in front of their parent stars and slightly block the light of the stars.
'Dirty' Collisions Shed Light on Planet Formation | Space
Planetary models are incredibly complex, requiring scientists to account for everything that happens to a growing planet on timescales spanning a few days to millions of years. In the past, astronomers would simplify their models of colliding objects by assuming that all of the material from both the impactor and its target perfectly merged into a single object — an unrealistic expectation, since at least some pieces would most likely be flung into space and lost.
In the past decade, however, improvements in computational power have allowed researchers to begin studying more-realistic collision scenarios. Now, scientists can model so-called hit-and-run collisions , where two bodies scraped each other in passing, or even the total annihilation that could occur when two planetary embryos slammed together. These imperfect "dirty collisions" not only affect how large planets grow to be but also help to explain their orbits.
This is the closest solar system to Earth containing multiple planets - CNN
(CNN) Just 11 light years from earth is the GJ 15 A star system with two planets orbiting a red-dwarf star. This makes it the closest solar system to Earth that contains multiple planets.
And here's another article:
Importance of Giant Impact Ejecta for Orbits of Planets Formed during the Giant Impact Era
Terrestrial planets are believed to be formed via giant impacts of Mars-sized protoplanets. Planets formed via giant impacts have highly eccentric orbits. A swarm of planetesimals around the planets may lead to eccentricity damping for the planets via the equipartition of random energies (dynamical friction). However, dynamical friction increases eccentricities of planetesimals, resulting in high velocity collisions between planetesimals.
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Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
NASA Just Picked New Planetary Missions to Study. Here Are The Most Exciting Ones
Look, Mars is great. It's full of great rocks , and those blue sunsets are just top-notch. But there's no denying it: Mars definitely gets way more attention than other planets. At time of writing, there are eight active probes on or orbiting Mars.
Other Solar System planets have their secrets too, and NASA has just funded a bunch of planetary mission concept studies to see what's feasible to explore in the near future.
These studies will be published in the 2023 Planetary Science Decadal Survey, a US National Research Council publication produced every 10 years or so, identifying key issues and outlining recommendations for the coming decade in planetary science.
Planets Align Over the 'White City' in Twilight Photo of Tel Aviv | Space
Saturn, Venus and Jupiter align above the skyline of Tel Aviv, Israel, as seen during the morning twilight.
Miguel Claro is a professional photographer, author and science communicator based in Lisbon, Portugal, who creates spectacular images of the night sky. As a European Southern Observatory Photo Ambassador and member of The World At Night and the official astrophotographer of the Dark Sky Alqueva Reserve , he specializes in astronomical "Skyscapes" that connect both Earth and night sky.
NASA news: Agency chief calls for major U-turn on Pluto as planet debate rages | Science | News |
“Some people have argued that in order to be a planet, you need to clear your orbit around the sun.
“Well, what we now know is that if that’s the definition that we’re gonna use, you could really undercut all the planets.
“They’re all dwarf planets because there isn’t a planet that clears its entire orbit around the sun.”
Mr Bridenstine is the latest in a long line of scientists who have disputed the change in Pluto’s status back in 2006.
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