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Sky-Tonight.com / Asteroids / 85 Io
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Observation Settings

Or select it on the map:
This Earth map fragment is intended to illustrate celestial motion across the sky, emphasizing both bearing and elevational perspectives. The map's center point corresponds to the transit, showcasing celestial objects at their highest point, while elevation gradually decreases towards the map edges. This dynamic representation offers insights into the changing positions of celestial bodies with a focus on their bearing and elevational trajectories.
Your location: Santa Clara, United States
Timezone:
Latitude:
37.3541
Longitude:
-121.955

Asteroid 85 Io Observation Details

Io

Io Daily Motion

Io will rise at 12:02, reaching 48° when twilight begins at 16:22. It will reach transit at 56° by 18:10 and will set before twilight ends at 00:17.
85 Io will be visible until March, 23, when it will move too close to the Sun. During this time, its proximity to the Sun will cause it to disappear from the night sky, making it unobservable for a while.

Io Visibility Timetable on December 08

Io Rise and Set Timetable

TimeElevation
Io rise12:02
Sunset14:4832°
Civil sunset15:1838°
Astrosession begin16:2248°
Moon Rise, 85.7% illuminated17:5755°
Io transit18:1056°
Io set00:17
Astrosession end03:36-36°
Moon Set08:54-34°

Track Io Position Throughout the Night

← Mon, 8 December 2025 →

Elevation (degrees)
Time
Altitude
Azimuth
Shift the map to change the time and observe Io changing position in the night sky.

Io Description

Io, designated as 85 Io, is a main-belt asteroid, located between Mars and Jupiter in the solar system. With a diameter of 154 km, 85 Io completes its orbit around the Sun in 4.3 years. At the moment, 85 Io is 1.742 AU (260,599,491 km) from Earth, and it is located in the constellation Pisces.

Current position of Io in Solar System

Earth Io
DateMon, 8 December 2025
Distance from Earth to Io1.746 AU (261,197,882km)
Elongation122°
Angular diameter"
Magnitude12.07
This section provides an interactive projection of the solar system, illustrating the relative positions of Io, Earth, and the Sun throughout the year. By sliding the image left or right, you can change the day of the year, observing how the positions of Io and Earth shift in their orbits around the Sun.

Finder Chart for Io

Double-click to unlock the map.
Object name85 Io
Field of view
Limiting magnitude
85 Io coordinates1.1810379274842, 2.9043730903296
Center coordinates1.1810379274842, 2.9043730903296

Annual motion of Io

Time
DateMon, 8 December 2025
Twighlight start16:18
Twighlight end03:30
Twighlight duration11h 11m
Rise11:58
Set00:14
Elevation at transit56°
Transit time18:06
Equatorial coordinatesRA: 01h 11m 11s", Dec: 02° 53' 14s
Magnitude12
ConstellationPisces
The graph illustrates the annual visibility pattern of a Io, providing a comprehensive overview of its daily appearances and transit times throughout the year.
The graph is structured with the vertical axis showing the hours of the day, ranging from 12 AM to 12 AM the next day, while the horizontal axis spans each day of the year.
The reddish shaded area indicates the periods when the Io is above the horizon, visible to observers. The white line marks the times when the celestial object reaches its highest point in the sky each day, known as the transit.

Astrometric & Physical Parameters of 85 Io

Coordinates & Visibility

Right Ascension1.1810379274842°
Declination2.9043730903296°
Magnitude12.07
ConstellationPisces
Elevation-46.9°
Azimuth-24.6°

Acknowledgments

We acknowledge NASA's Jet Propulsion Laboratory (JPL) for providing essential data on asteroids and comets through their Small-Body Database (SBDB) and Center for Near-Earth Object Studies (CNEOS). Their continuous efforts in tracking and cataloging these celestial bodies make it possible to offer accurate and up-to-date information on their positions, orbits, and physical characteristics.