Paul R. Estrada
@drpaulestrada.bsky.social
Planetary Scientist - Early history and evolution of protoplanetary disks; origins and dynamics of gas and ice giant rings and moons; father to teens; Australian Shepherd(s) dad.
On the other hand, this guy could be duping all of you.
October 1, 2025 at 5:43 AM
On the other hand, this guy could be duping all of you.
For those who would like a sense of the meaning of today's NASA presser on the Mars discovery, here is an excellent take from a colleague.
Mars Discovery Raises Compelling Questions: Life or Chemistry
Results from NASA’s Perseverance rover presented this morning in a NASA press conference show the presence of organic molecules, unusual minerals, and strange textures inside Jezero’s ancient lakebed ...
www.seti.org
September 11, 2025 at 5:15 AM
For those who would like a sense of the meaning of today's NASA presser on the Mars discovery, here is an excellent take from a colleague.
Image of the super giant star Antares, at a distance of 555 light years, taken with the Very Large Telescope Interferometer (VLTI) in Chile. The tiny dot on the bottom left would be roughly the size of the Sun. At only ~15 Myr old, these stars live fast and die hard (supernova).
December 27, 2024 at 9:06 PM
Image of the super giant star Antares, at a distance of 555 light years, taken with the Very Large Telescope Interferometer (VLTI) in Chile. The tiny dot on the bottom left would be roughly the size of the Sun. At only ~15 Myr old, these stars live fast and die hard (supernova).
JWST image of Uranus and it's rings AND inner moons. Clockwise are Rosalind, Puck, Belinda, Desdemona, Cressida, Bianca, Portia, Juliet and Perdita in the most tight orbital configuration known. Subject to chaos as a result, their collisions possibly supply ring material on ~million yr timescales.
December 5, 2024 at 6:37 AM
JWST image of Uranus and it's rings AND inner moons. Clockwise are Rosalind, Puck, Belinda, Desdemona, Cressida, Bianca, Portia, Juliet and Perdita in the most tight orbital configuration known. Subject to chaos as a result, their collisions possibly supply ring material on ~million yr timescales.
Yes, Saturn's ring do cast shadows on the surface.
Cassini image taken in 2005. Mimas and Tethys are visible.
Incidentally, the rings are about half the mass of Mimas (that smaller dot), but have a surface area about 10000-100000 times that of Mimas (and are only 10's of meters thick).
Cassini image taken in 2005. Mimas and Tethys are visible.
Incidentally, the rings are about half the mass of Mimas (that smaller dot), but have a surface area about 10000-100000 times that of Mimas (and are only 10's of meters thick).
November 16, 2024 at 1:24 AM
Yes, Saturn's ring do cast shadows on the surface.
Cassini image taken in 2005. Mimas and Tethys are visible.
Incidentally, the rings are about half the mass of Mimas (that smaller dot), but have a surface area about 10000-100000 times that of Mimas (and are only 10's of meters thick).
Cassini image taken in 2005. Mimas and Tethys are visible.
Incidentally, the rings are about half the mass of Mimas (that smaller dot), but have a surface area about 10000-100000 times that of Mimas (and are only 10's of meters thick).