Sep 16, 2020 06:13 PM
Uranian Moons Are Like Dwarf Planets
https://skyandtelescope.org/astronomy-ne...f-planets/
EXCERPTS: The five large moons of the ice giant Uranus resemble the dwarf planets in the outer solar system, such as Pluto, Eris, and Haumea. It’s not that all these worlds necessarily look the same, but they have similar heat signatures, according to a German-Hungarian team of astronomers. Like the large dwarf planets, the Uranian moons retain solar heat very well, and their night sides cool down relatively slowly - typical of the rough, icy surfaces of large, compact objects.
[...] Meg Schwamb agrees that it’s “a neat result with a cool technique”, but she’s not very surprised that the five large moons resemble the Kuiper Belt’s dwarf planets. After all, according to current understanding, objects like Pluto, Eris, and Haumea formed in the same region of the solar system as Uranus. “Similar locations in the protoplanetary disk would mean similar conditions in terms of temperature, gas composition, et cetera,” she says, which suggests that the major Uranian moons would form with similar surface properties and compositions as the dwarf planets. By contrast, the many smaller outer moons of Uranus appear to be more like smaller Kuiper Belt objects: relatively loose aggregates of rock and ice... (MORE - details)
In A Complete Fluke, A European Spacecraft Is About To Fly Past Venus – And Could Look For Signs Of Life
https://www.forbes.com/sites/jonathanoca...s-of-life/
EXCERPT: Earlier this week, scientists announced the discovery of phosphine on Venus, a potential signature of life. [...] As luck would have it, a joint spacecraft from the European Space Agency (ESA) and Japanese space agency (JAXA) is about to fly past Venus that could tell us for sure.
BepiColombo, launched in 2018, is on its way to enter orbit around Mercury, the innermost planet of the Solar System. But to achieve that it plans to use two flybys of Venus to slow itself down, one on October 15, 2020, and another on August 10, 2021.
The teams running the spacecraft already had plans to observe Venus during the flyby. But now, based on this detection of phosphine from telescopes on Earth, they are now planning to use both of these flybys to look for phosphine using an instrument on the spacecraft. “We possibly could detect phosphine,” says ESA's Johannes Benkhoff, BepiColombo's Project Scientist. “But we do not know if our instrument is sensitive enough.”
The instrument, called MERTIS (MErcury Radiometer and Thermal Infrared Spectrometer), is designed to study the composition of the surface of Mercury. However, the team believe they can also use it to study the atmospheric composition of Venus during both flybys. On this first flyby, the spacecraft will get no closer than 10,000 kilometers from Venus. That’s very far, but potentially still close enough to make a detection.
[...] As this first flyby is only weeks away, however, the observation campaign of the spacecraft is already set in stone, making the chance of a discovery slim. More promising is the second flyby next year, which will not only give the team more time to prepare, but also approach just 550 kilometers from Venus... (MORE - details)
https://skyandtelescope.org/astronomy-ne...f-planets/
EXCERPTS: The five large moons of the ice giant Uranus resemble the dwarf planets in the outer solar system, such as Pluto, Eris, and Haumea. It’s not that all these worlds necessarily look the same, but they have similar heat signatures, according to a German-Hungarian team of astronomers. Like the large dwarf planets, the Uranian moons retain solar heat very well, and their night sides cool down relatively slowly - typical of the rough, icy surfaces of large, compact objects.
[...] Meg Schwamb agrees that it’s “a neat result with a cool technique”, but she’s not very surprised that the five large moons resemble the Kuiper Belt’s dwarf planets. After all, according to current understanding, objects like Pluto, Eris, and Haumea formed in the same region of the solar system as Uranus. “Similar locations in the protoplanetary disk would mean similar conditions in terms of temperature, gas composition, et cetera,” she says, which suggests that the major Uranian moons would form with similar surface properties and compositions as the dwarf planets. By contrast, the many smaller outer moons of Uranus appear to be more like smaller Kuiper Belt objects: relatively loose aggregates of rock and ice... (MORE - details)
In A Complete Fluke, A European Spacecraft Is About To Fly Past Venus – And Could Look For Signs Of Life
https://www.forbes.com/sites/jonathanoca...s-of-life/
EXCERPT: Earlier this week, scientists announced the discovery of phosphine on Venus, a potential signature of life. [...] As luck would have it, a joint spacecraft from the European Space Agency (ESA) and Japanese space agency (JAXA) is about to fly past Venus that could tell us for sure.
BepiColombo, launched in 2018, is on its way to enter orbit around Mercury, the innermost planet of the Solar System. But to achieve that it plans to use two flybys of Venus to slow itself down, one on October 15, 2020, and another on August 10, 2021.
The teams running the spacecraft already had plans to observe Venus during the flyby. But now, based on this detection of phosphine from telescopes on Earth, they are now planning to use both of these flybys to look for phosphine using an instrument on the spacecraft. “We possibly could detect phosphine,” says ESA's Johannes Benkhoff, BepiColombo's Project Scientist. “But we do not know if our instrument is sensitive enough.”
The instrument, called MERTIS (MErcury Radiometer and Thermal Infrared Spectrometer), is designed to study the composition of the surface of Mercury. However, the team believe they can also use it to study the atmospheric composition of Venus during both flybys. On this first flyby, the spacecraft will get no closer than 10,000 kilometers from Venus. That’s very far, but potentially still close enough to make a detection.
[...] As this first flyby is only weeks away, however, the observation campaign of the spacecraft is already set in stone, making the chance of a discovery slim. More promising is the second flyby next year, which will not only give the team more time to prepare, but also approach just 550 kilometers from Venus... (MORE - details)