Blog about planets.

Aganippe Fossa

ESA has published an image captured by its Mars Express space probe’s High Resolution Stereo Camera (HRSC) instrument of Aganippe Fossa, a formation that has the appearance of a scar on the surface of the planet Mars which is truly colossal given that it’s approximately 600 kilometers long. This rift valley is a geological formation of the type called graben in jargon. There are no certainties about its formation but it’s probably linked to lava flows under the enormous volcanoes of the Tharsis region, starting with Arsia Mons, the closest to Aganippe Fossa.

On the left the planet Jupiter seen by the James Webb Space Telescope's Near-Infrared Camera (NIRCam) instrument and on the right the Great Red Spot observed by the Near-InfraRed Spectrograph (NIRSpec) instrument

An article published in the journal “Nature Astronomy” reports the identification of structures in the planet Jupiter’s upper atmosphere above the Great Red Spot, the iconic storm larger than the Earth. A team of researchers led by Henrik Melin of the British University of Leicester used observations conducted with the James Webb Space Telescope to obtain new details of that area. The surprise came from the identification of intricate structures including dark arcs and bright spots in the observed area.

The Ceraunius Tholus volcano as seen by the TGO space probe's CaSSIS instrument with the frost in blueish

An article published in the journal “Nature Geoscience” reports the detection of frost on volcanoes in the Tharsis region on Mars. A team of researchers used data obtained from two ESA space probes, the ExoMars mission’s TGO and Mars Express, which made it possible to discover for the first time the presence of frozen water on the Martian surface at the red planet’s equator. In the calderas of the big volcanoes of Tharsis, blue deposits that can be attributed to water ice were spotted which are present only in the morning and then evaporate a few hours later.

The Earth and artistic concepts showing the exoplanet Gliese 12 b in possible versions ranging from no atmosphere to a very thick atmosphere like that of Venus

Two articles, one published in the journal “Monthly Notices of the Royal Astronomical Society” and one in “The Astrophysical Journal Letters”, report independent confirmations of the discovery of the exoplanet Gliese 12 b, which has a size very close to the Earth’s but orbits a red dwarf that has a mass and size that are around a quarter of the Sun’s. Two teams of researchers used observations conducted by NASA’s TESS space telescope and confirmations obtained with other instruments to verify the existence of Gliese 12 b. The available information doesn’t reveal if it has an atmosphere but several factors make it a good candidate for a follow-up search with the James Webb Space Telescope.

Artistic representation of the exoplanet WASP-193 b

An article published in the journal “Nature Astronomy” reports the identification of the exoplanet WASP-193 b, a gas giant whose diameter is approximately 1.5 times Jupiter’s but with a mass that is only one-seventh of Jupiter’s. A team of researchers led by Khalid Barkaoui of the University of Li├Ęge, Belgium, used the WASP-South telescope of the Wide Angle Search for Planets (WASP) collaboration to locate WASP-193 b and then study its characteristics with other instruments. The combination of this exoplanet’s mass and density is really difficult to explain since no theory of planetary formation leads to a planet like this.