7 Iris is a large main-belt asteroid located between the orbits of Mars and Jupiter. It orbits the Sun once every 3.68 Earth years. It was discovered on August 13, 1847 by John Russell Hind and is named after the Greek goddess of the rainbow. Iris has a diameter of approximately 200 kilometers and is irregularly shaped, with a rotation period of about 7.1 hours. In 2007, the European Space Agency launched the Rosetta spacecraft, which passed within 5 million kilometers of Iris and obtained detailed measurements of its surface. These observations, together with ground-based radar observations, revealed that Iris has a highly elongated shape and provided important insights into its rotational dynamics. The study of Iris and its family of asteroids has provided important insights into the formation and evolution of the asteroid belt and the early solar system.
Find it in the Sky
Chose a date & time and view the position of asteroid 7 Iris in the sky on our interactive planetarium.
In Evidence
Asteroid 7 Iris
Asteroid 7 Iris is in the constellation of Gemini, at a distance of
Finder Charts
The sky charts below show, at different resolutions, the position of asteroid 7 Iris in the sky. Click on each chart to access the interactive star map tool.
The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of asteroid 7 Iris against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.
Equatorial Coordinates
Apparent
J2000
Additional Information
Rise and Set Times
The following table lists today's rise, transit and set times of asteroid 7 Iris from Cairo, Egitto (all times relative to the local timezone Africa/Cairo):
If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.
Distance from Earth
The distance of asteroid 7 Iris from Earth is currently
The following graph shows the distance of asteroid 7 Iris from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).
The value of the distance of 7 Iris from Earth is also available as a real time updated value in the live position tracker.
Closest Approach to Earth
In the period between January 1, 1900 and December 31, 2099, the closest approach of asteroid 7 Iris to Earth happened on Saturday 8 November 1947 at a distance of 0.846460 Astronomical Units, or 126,628,540 kilometers:
Note: the values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart shows the light curve of asteroid 7 Iris, i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.
Orbital Elements
The following table lists the orbital elements of asteroid 7 Iris at epoch February, 24 2023 00:00 UTC (JD: 2460000.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.22965976 |
| Orbit inclination | i | 5.51780097° |
| Perihelion distance | q | 1.83876388 AU 275,075,162 km |
| Aphelion distance | Q |
2.93513675 AU 439,090,209 km |
| Semi-major axis | a |
2.38695031 AU 357,082,685 km |
| Orbital period | period |
3.6879 years 1,346.9873 days |
| Date of perihelion transit | Tp | July 26, 2021 2,459,422.4910 JD |
| Next perihelion transit | April 3, 2025 2,460,769.4783 JD |
|
| Argument of perihelion | peri | 145.41271894919° |
| Longitude of the ascending node | node | 259.50440351462° |
| Mean anomaly | M | 154.48048287592° |
| Mean motion | n | 0.26726310°/day |
Orbit Visualization
The following chart is a 3D animated visualization of the orbit of asteroid 7 Iris relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.
Physical Properties
The table below lists the known key physical properties of asteroid 7 Iris. The source for this data is the JPL Small-Body Database.
| Physical Parameter | Value | Relative to Earth |
|---|---|---|
| Diameter | 199.83 km | 0.0157 |
| Sideral Rotation | 7.1390 hours | 0.2983 |
| Absolute Magnitude | 5.51 | |
| Geometric Albedo | 0.2766 |
15 Days Ephemeris
The following table lists the ephemerides of asteroid 7 Iris computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.
| Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
|---|---|---|---|---|
| Jul 05 2025 | 06h 04m 11s | +23° 08’ 19” | 9.85 | Gemini |
| Jul 06 2025 | 06h 06m 44s | +23° 06’ 25” | 9.86 | Gemini |
| Jul 07 2025 | 06h 09m 17s | +23° 04’ 23” | 9.87 | Gemini |
| Jul 08 2025 | 06h 11m 49s | +23° 02’ 11” | 9.88 | Gemini |
| Jul 09 2025 | 06h 14m 20s | +22° 59’ 51” | 9.89 | Gemini |
| Jul 10 2025 | 06h 16m 52s | +22° 57’ 20” | 9.90 | Gemini |
| Jul 11 2025 | 06h 19m 23s | +22° 54’ 42” | 9.91 | Gemini |
| Jul 12 2025 | 06h 21m 54s | +22° 51’ 54” | 9.92 | Gemini |
| Jul 13 2025 | 06h 24m 25s | +22° 48’ 57” | 9.93 | Gemini |
| Jul 14 2025 | 06h 26m 55s | +22° 45’ 51” | 9.94 | Gemini |
| Jul 15 2025 | 06h 29m 25s | +22° 42’ 36” | 9.95 | Gemini |
| Jul 16 2025 | 06h 31m 55s | +22° 39’ 13” | 9.96 | Gemini |
| Jul 17 2025 | 06h 34m 24s | +22° 35’ 41” | 9.97 | Gemini |
| Jul 18 2025 | 06h 36m 53s | +22° 32’ 01” | 9.97 | Gemini |
Additional Resources on TheSkyLive
- Asteroid 7 Iris: Complete reference information on TheSkyLive.com.
- Where is asteroid 7 Iris?: Key information on where to find asteroid 7 Iris in the sky.
- Distance of asteroid 7 Iris from Earth: Find out how far asteroid 7 Iris is from Earth right now.
- How Bright is asteroid 7 Iris?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Rise and set times of asteroid 7 Iris from your location.
- Interactive Sky Map: Planetarium-style interactive visualization of asteroid 7 Iris's position in the sky.
- Live Position Tracker: High precision real time tracker of asteroid 7 Iris's position using deep space imagery.
- Ephemeris: 15 days asteroid 7 Iris's computed ephemeris.
- Orbital elements: Information about asteroid 7 Iris orbital parameters.
- Orbit Visualization: 3D interactive visualization showing the orbit of asteroid 7 Iris with respect to the major Solar System objects.
- Physical Data: Detailed information about physical properties of asteroid 7 Iris.