interstellar objects Archives

Semimajor axis distribution of captured ISOs in three simulations, each with stellar mass M⋆ = 0.7 M⊙ and impact parameter b = 3000 au, but with velocity at infinity v∞ = 1, 3, and 10 km/s. -- [astro-ph.EP]

Interstellar

Interstellar Objects During Stellar Encounters

by Keith CowingJuly 23, 2026July 23, 2026

[astro-ph.EP] As they orbit within the Galaxy, stars swim through a vast population of interstellar objects (ISOs).

Summary of ISO stream morphologic properties. The top four panels compare the width, height, length, and peak density of a set of simulated streams to rules of thumb for each of these quantities. In the bottom row, the velocity dispersion along the 3 different axes of the stream is compared to the initial velocity dispersion σ0. The bottom right panel shows the shape parameters of the density distribution. In each panel, 5 points are shown for each stream, corresponding to 5 randomly-selected times between 0 and 10 Gyr. For the most part we expect streams to follow the 1:1 line shown in these panels, and for the most part they do, over 3+ orders of magnitude. The exception is σL, the velocity dispersion along the stream direction, which is typically far less than σ0, since a particle’s position in the stream is primarily determined by its velocity in this direction. Note that for plotting clarity we have included a small random scatter of 0.07 dex on the x-coordinates of points where the x-axis is σ0 times a constant, since many points have identical values. -- astro-ph.EP

Comets and Asteroids, Panspermia, Status Report

He Awa Whiria: The Tidal Streams of Interstellar Objects

by Keith CowingNovember 28, 2024November 28, 2024

Upcoming surveys are likely to discover a new sample of interstellar objects (ISOs) within the Solar System, but questions remain about the origin and distribution of this population within the […]

interstellar objects

Interstellar Objects During Stellar Encounters

He Awa Whiria: The Tidal Streams of Interstellar Objects

Astrobiologist Dale Andersen’s Antarctic Field Report: 11 November 2026: Weather Update And Forecast

Astrobiologist Dale Andersen’s Antarctic Field Report: 10 November 2026: Weather Update Forecast

Dispersal of Bacterial Spores Away From Spacecraft on the Martian Surface is Unlikely to Contaminate Subsequent Life-detection Samples

From Exo-Earth Detection to Atmospheric Characterization: Enabling Phase-Dependent Molecular Detection SNR in EXOSIMS

Ancient Rocks Reveal When Earth’s Tectonic Engine Switched On