Tag: astronomy

500 exo-comets

Astronomers have studied 500 comets orbiting the Beta Pictoris and have discovered that they belong to 2 distinct families of exocomets: old exocomets that have made multiple passages near the star, and younger exocomets that probably came from the recent breakup of 1 or more larger objects. Beta Pictoris is a young star located 63 light-years from the Sun. It is only 20 ga old and is surrounded by a huge disc of material — a very active young planetary system where gas and dust are produced by the evaporation of comets and the collisions of asteroids.

GRBs extinguish life in the Universe

There is a 50% chance that a GRB took place during the last 500 Myr causing one of the major mass extinction events. The probability of a lethal GRB is much larger in the inner Milky Way, making it inhospitable to life. The safest environments for life are the lowest density regions in the outskirts of large galaxies and life can exist in only ~10% of galaxies.

the most plausible explanation of the fermi paradox yet.

Ultimate solar system

we’re about a factor 10x off from an ideal solar system

2 of our chosen stars on a wide orbit. Each hosts 1 of the systems we just built. That makes a total of 60 habitable worlds in a single system! 24 in ultimate system 1 and 36 in ultimate system The ultimate Solar System makes a great setting for storytelling. Just imagine! Wars between moons orbiting the same gas giant planet. Coalitions, alliances, trickery! High-end worlds with their own dedicated beach moons. Worlds launching long-range missiles at their Trojan counterparts. Intelligent beings who learn orbital dynamics at a very young age. Prison worlds that revolt! Plus, if 1 species took over all of the worlds orbiting 1 of the stars, there could be a whole other series of battles with the worlds orbiting the other star.

Galaxy Full of Planets?

there are 40B earth-like planets in the habitable zone in the galaxy.

2014-12-05:

the number of biotic planets in the Milky Way is between millions and billions, and the corresponding distance to the nearest biotic world is 10-100 light years. the likely distance to the nearest civilizations detectable by SETI is of the order of a few 1000 light years

this is a very accessible paper on the Drake equation (which may well achieve a cultural status similar to e=mc^2 this century)

1% of the stars in the Milky Way could have earth like planets (smaller rock like planets) Another study shows the Milky Way is twice as big as previously thought. So instead 100b stars there could be 200b and of those 1% or 2b could have earth like worlds around sun like stars.

Mapping 1b stars

During the mapping, Gaia will detect and very accurately measure the motion of each star in its orbit around the center of the Galaxy. During its anticipated lifetime of 5 years, Gaia will observe each of its 1b sources 70x, resulting in a record of the brightness and position of each source over time. Together with the unprecedented accuracy of the astrometric measurements, this will lead to the discovery of: planets around other stars, asteroids in our Solar System, icy bodies in the outer Solar System, brown dwarfs, and far-distant supernovae and quasars. The list of Gaia’s potential discoveries makes the mission unique in scope and scientific return.