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Asteroid Near-Earth Potentially hazardous

Geographos

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1620 Geographos (1951 RA)

Where is it now

Distance from Sun
1.329 AU
True anomaly
120.01°
Distance from Earth
0.381 AU
As of
11 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Sun Earth — 0.998 AU from the Sun Earth Geographos — 1.329 AU from the Sun Geographos
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Geographos is 0.381 AU from Earth today (3.2 light-minutes).

In the sky

Right ascension
23h 03m 38s
Declination
+25° 37′ 44″
Constellation
Pegasus
Distance from Earth
0.39 AU
Elongation from the Sun
144.79° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
1.246 AU
Eccentricity
0.3355
Inclination
13.34°
Orbital period
507.9 days
Perihelion
0.828 AU
Aphelion
1.664 AU
Longitude of ascending node
337.13°
Argument of periapsis
277.03°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 11.5 LD
0.0295 AU
Tisserand (Jupiter)
5.074

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
10,105
Data arc
75.07 years
First observed
14 September 1951
Last observed
9 October 2026
Residual RMS
0.28 ″
Solution · Otto Matic
10 October 2026

Physical properties

Mean radius
1.28 km
Rotation period
5.22 hours
Shape · km
5.0x2.0x2.1

Visual & observation

Geometric albedo
0.29
Absolute magnitude (H)
15.27
Colour index (B–V)
0.86
Spectral type (SMASS)
S
Spectral type (Tholen)
S
Colour index (U–B)
0.47

Discovery & classification

Discovered by
Wilson, A. G., Minkowski, R.
Discovery date
14 September 1951
Discovery site
Palomar

Also known as 1620 · 1951 RA · 1983 CY3

Apollo Near-Earth Object Named Potentially Hazardous Asteroid

Close approaches 28 on record

Flyby geometry
Ecliptic flyby of Geographos at 2040-03-12 10:58 UTC Top-down view of the ecliptic, Earth at the centre, for the 2040-03-12 10:58 UTC close approach of Geographos. Catalogue miss distance 44.2 LD · 1.7 × 10⁷ km. The curve is the geocentric path from 2040-03-09 to 2040-03-15, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. At closest approach the object is south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 44.2 LD · 1.7 × 10⁷ km 2040-03-12 10:58 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2040-03-12 10:58 UTC close approach of Geographos. Catalogue miss distance 44.2 LD · 1.7 × 10⁷ km. The curve is the geocentric path from 2040-03-09 to 2040-03-15, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. At closest approach the object is south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2040-03-12 10:58:00 Earth 0.1136 AU 44.2 LD 13.7 km/s
2051-08-23 03:35:00 Earth 0.0479 AU 18.6 LD 11 km/s
2065-03-13 19:56:00 Earth 0.0966 AU 37.6 LD 13 km/s
2076-08-20 09:35:00 Earth 0.0784 AU 30.5 LD 10.2 km/s
2090-03-11 06:39:00 Earth 0.1508 AU 58.7 LD 15 km/s
2094-09-03 10:34:00 Earth 0.19 AU 74.0 LD 16.7 km/s
2101-08-07 02:26:00 Earth 0.198 AU 77.1 LD 8 km/s
2108-03-18 23:57:00 Earth 0.1396 AU 54.3 LD 9.4 km/s
2119-08-27 16:11:00 Earth 0.0336 AU 13.1 LD 12.4 km/s
2133-03-18 05:51:00 Earth 0.1006 AU 39.1 LD 10.7 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources