Primitive objects like comets hold important information on the material that formed our solar
system. Several comets have been visited by spacecraft and many more have been …

We provide the first solar system wide compendium of speleogenic processes and products.
An examination of 15 solar system bodies revealed that six cave‐forming processes occur …

Understanding how comets work—what drives their activity—is crucial to the use of comets
in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact …

Pits have been observed on many cometary nuclei mapped by spacecraft,,,. It has been
argued that cometary pits are a signature of endogenic activity, rather than impact craters …

We critically review the data on the sizes, shapes, albedos, and colors of cometary nuclei.
Reliable sizes have been determined for 65 ecliptic comets (ECs) and 13 nearly isotropic …

Every three years the IAU/IAG Working Group on cartographic coordinates and rotational
elements of the planets and satellites revises tables giving the directions of the north poles …

INTRODUCTION On 1 January 2019, the New Horizons spacecraft passed 3538 km from
Kuiper Belt object (KBO)(486958) Arrokoth. Arrokoth is a contact binary consisting of two …

We simulate experimentally the physical conditions present in dense clouds by means of a
high vacuum experimental setup at low temperature T≈ 12 K. The accretion and …

So-called 'dark comets' are small, morphologically inactive near-Earth objects (NEOs) that
exhibit nongravitational accelerations inconsistent with radiative effects. These objects …

Observations of cometary nuclei have revealed a very limited amount of surface water
ice,,,,,,, which is insufficient to explain the observed water outgassing. This was clearly …