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Asteroid Near-Earth

Ubasti

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4257 Ubasti (1987 QA)

Where is it now

Distance from Sun
2.324 AU
True anomaly
162.54°
Distance from Earth
2.949 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth Ubasti — 2.324 AU from the Sun Ubasti
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Ubasti is 2.949 AU from Earth today (24.5 light-minutes).

In the sky

Right ascension
15h 45m 22s
Declination
+11° 33′ 06″
Constellation
Serpens
Distance from Earth
2.95 AU
Elongation from the Sun
42.97° — near the Sun — look low at dusk or dawn

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.

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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
1.647 AU
Eccentricity
0.4683
Inclination
40.72°
Orbital period
772 days
Perihelion
0.876 AU
Aphelion
2.418 AU
Longitude of ascending node
169.14°
Argument of periapsis
278.95°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 66.1 LD
0.1698 AU
Tisserand (Jupiter)
3.913

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
3,317
Data arc
38.93 years
First observed
23 August 1987
Last observed
29 July 2026
Residual RMS
0.43 ″
Solution · Otto Matic
2 September 2026

Physical properties

Rotation period
4.4 hours

Visual & observation

Absolute magnitude (H)
15.97

Discovery & classification

Discovered by
Mueller, J. E.
Discovery date
23 August 1987
Discovery site
Palomar

Ubasti, also called Bastet or Bast, was an ancient Egyptian goddess worshiped in the form of a cat. Originally a goddess of the home, in the New Kingdom Ubasti was equated with the lioness war goddess. This name is being dedicated to observatory cats throughout the world. Name suggested and citation prepared by G. V. Williams at the request of the discoverer.

Also known as 4257 · 1987 QA

Apollo Near-Earth Object Named

Close approaches 7 on record

Flyby geometry
Ecliptic flyby of Ubasti at 2064-03-04 13:35 UTC Top-down view of the ecliptic, Earth at the centre, for the 2064-03-04 13:35 UTC close approach of Ubasti. Catalogue miss distance 67.2 LD · 2.58 × 10⁷ km. The curve is the geocentric path from 2064-03-01 to 2064-03-07, 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 67.2 LD · 2.58 × 10⁷ km 2064-03-04 13:35 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2064-03-04 13:35 UTC close approach of Ubasti. Catalogue miss distance 67.2 LD · 2.58 × 10⁷ km. The curve is the geocentric path from 2064-03-01 to 2064-03-07, 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
2064-03-04 13:35:00 Earth 0.1727 AU 67.2 LD 24 km/s
2133-07-05 05:22:00 Mars 0.0642 AU 25.0 LD 21.6 km/s
2138-03-04 00:43:00 Earth 0.1784 AU 69.4 LD 22.9 km/s
2150-06-05 15:12:00 Mars 0.027 AU 10.5 LD 22.5 km/s
2157-03-07 15:32:00 Earth 0.1958 AU 76.2 LD 25.1 km/s

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

Sources