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Asteroid

Siwa

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140 Siwa (A874 TB)

Where is it now

Distance from Sun
2.606 AU
True anomaly
269.43°
Distance from Earth
3.597 AU
As of
21 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.995 AU from the Sun Earth Siwa — 2.606 AU from the Sun Siwa
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Siwa is 3.597 AU from Earth today (29.9 light-minutes).

In the sky

Right ascension
14h 03m 33s
Declination
-10° 11′ 28″
Constellation
Virgo
Distance from Earth
3.6 AU
Elongation from the Sun
4.42° — too close to the Sun to observe

Visible from both hemispheres.

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
2.73 AU
Eccentricity
0.2182
Inclination
3.19°
Orbital period
4.51 years
Perihelion
2.134 AU
Aphelion
3.326 AU
Longitude of ascending node
107.08°
Argument of periapsis
197.2°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 435.3 LD
1.1187 AU
Tisserand (Jupiter)
3.318

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
7,328
Data arc
149.1 years
First observed
11 March 1877
Last observed
13 April 2026
Residual RMS
0.38 ″
Solution · Otto Matic
5 June 2026

Physical properties

Mean radius
55 km
Rotation period
34.45 hours

Visual & observation

Geometric albedo
0.068
Absolute magnitude (H)
8.45
Colour index (B–V)
0.72
Spectral type (SMASS)
Xc
Spectral type (Tholen)
P
Colour index (U–B)
0.3

Discovery & classification

Discovered by
Palisa, J.
Discovery date
13 October 1874
Discovery site
Pola

Also known as 140 · A874 TB · 1948 AL

Main-Belt Asteroid Named

Close approaches 7 on record

When (UTC) Body Distance Lunar distances Relative speed
2060-12-08 09:50:00 Juptr 1.9496 AU 758.7 LD 2 km/s
2097-07-17 13:18:00 Juptr 1.935 AU 753.0 LD 1.6 km/s
2155-10-13 12:49:00 Juptr 1.9732 AU 767.9 LD 2.1 km/s
2192-05-21 17:42:00 Juptr 1.9303 AU 751.2 LD 1.6 km/s

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

Sources