标签：#astronomy

The FCC authorized Reflect Orbital to launch the mirror satellite Eärendil-1. “For optical astronomy, this poses an existential threat,” the European Southern Observatory said.

It's unclear how the planet avoided its star's bloated red giant stage.

Something on Pluto and one of Saturn’s moons, Titan, absorbs light in a way unexplained by anything in spectroscopic databases.

A new study suggests that when our star becomes unstable in 5 billion years or so, Earth may avoid being engulfed by its fiery demise.

A study based on 47 million galaxies found that the cosmic web retains patterns on enormous scales, which could force a reevaluation of a pillar of cosmology.

The heat of the Hadean may have come from impacts as well as the interior.

Walkthrough experience includes visits to stars, exoplanets, and observatories.

The Euclid space telescope's stunning photo of our galaxy's “crowded heart” captures more than 60 million stars.

The asteroid will be visible for several nights from different parts of the world. We’ll tell you when and where to look, and what equipment you’ll need to spot it.

At the right point of the orbit and stellar cycle, the star's chromosphere brightens.

Researchers say the discovery could be a “Rosetta stone” for cosmic signals.

"I consider this a success already, just from the fact that we're even going to try this."

University of Leicester historian thinks Eilmer of Malmesbury saw two different comets: in 1018 and 1066

New simulations reveal that the moons of Uranus may retain traces of giant planets.

Stop shipping a 1990s C library to compute planets. Xalen is the pure-Rust, Apache-2.0 replacement for Swiss Ephemeris. If your app does astrology, you already know the dependency. Swiss Ephemeris: a C library from the 1990s, a folder of binary .se1 data files you have to ship and locate at runtime, and a license that is either AGPL or you pay for a commercial seat. For 30 years it was the only serious option, so everyone just swallowed the cost. That era is over. Xalen Ephemeris is a full planetary engine written in pure Rust, with no unsafe in the core engine (the only unsafe lives in the optional FFI, Node and WASM binding crates), released under Apache-2.0. No C toolchain. No data files to ship. No copyleft clause waiting for the day you try to make money. It is built to replace Swiss Ephemeris in production, not to admire it from a distance. Python is live on PyPI and the Rust crates are live on crates.io: # Python pip install xalen # Rust cargo add xalen-ephem xalen-time xalen-ayanamsa xalen-vedic Node and WASM build straight from the repo. Repo: https://github.com/vedika-io/xalen-ephemeris Switching takes one line Xalen ships a pyswisseph-shaped API on purpose. Migrating an existing codebase is a find-and-replace: # before import swisseph as swe # after import xalen.swe as swe jd = swe . julday ( 1990 , 6 , 15 , 10.5 ) xx , ok = swe . calc_ut ( jd , swe . SUN , swe . FLG_SWIEPH | swe . FLG_SPEED ) # same argument order, same SE_/SEFLG_/SIDM_ constants, same tuple layout Your function calls do not change. Your data-file directory disappears. Your license problem disappears. Xalen vs Swiss Ephemeris Line them up and the gap is hard to miss. Swiss Ephemeris is C from the 1990s, shipped as a native library you compile and link, fed by .se1 data files you have to bundle and locate at runtime, under AGPL or a paid commercial license. Xalen is pure Rust with no unsafe in the core engine, thread-safe, with no native dependency and no data files for the analytical eng

The black hole accounts for over two-thirds the mass of the object it inhabits.