Johnston's Archive

Astronomy and Space

Asteroids and TNOs with satellites (508 systems, 528 companions as of 28 November 2023)

Pluto and its moons (Pluto system summary information and images, following New Horizons flyby)

A TEXAN definition of a planet

1I 'Oumuamua (2017 U1): The first interstellar object within our solar system

solar system, general:

various topics:





other trans-Neptunian planets:

trans-Neptunian objects:


interstellar objects within the solar system:

solar system exploration:

stellar and extrasolar planet information:

relativistic objects:

other material:

A brief commentary on sky watching--a synopsis of things to look for in the night sky and links for more information. Some specific information for observers in parts of Texas is included.

Observing man-made Earth satellites--a discussion of how to look for visible satellites in the night sky.

Heaven's Above predictions for viewing satellites from Brownsville, TX (external link)

Links for sky watchers

Astronomy information links

Other space links

Banner image: Io and Jupiter, taken by Cassini in 2000 (credit: NASA/JPL/Univ. of Arizona).

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Last modified 28 November 2023.
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