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Asteroid Near-Earth Potentially hazardous

390725

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390725 (2003 HB)

Where is it now

Distance from Sun
1.171 AU
True anomaly
184.11°
Distance from Earth
2.151 AU
As of
19 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 — 0.996 AU from the Sun Earth 390725 — 1.171 AU from the Sun 390725
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 390725 is 2.151 AU from Earth today (17.9 light-minutes).

In the sky

Right ascension
13h 42m 32s
Declination
-02° 46′ 28″
Constellation
Virgo
Distance from Earth
2.15 AU
Elongation from the Sun
7.61° — 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
0.85 AU
Eccentricity
0.3803
Inclination
18.12°
Orbital period
286.1 days
Perihelion
0.527 AU
Aphelion
1.173 AU
Longitude of ascending node
70.34°
Argument of periapsis
306.75°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 17.9 LD
0.046 AU
Tisserand (Jupiter)
6.834

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
499
Data arc
22.09 years
First observed
21 April 2003
Last observed
22 May 2025
Residual RMS
0.35 ″
Solution · Otto Matic
2 July 2025

Physical properties

Mean radius
0.15 km

Visual & observation

Geometric albedo
0.271
Absolute magnitude (H)
19.69

Discovery & classification

Discovered by
LINEAR
Discovery date
21 April 2003
Discovery site
Socorro

Also known as 2003 HB

Aten Near-Earth Object Potentially Hazardous Asteroid

Close approaches 74 on record

Flyby geometry
Ecliptic flyby of 390725 at 2036-05-18 21:52 UTC Top-down view of the ecliptic, Earth at the centre, for the 2036-05-18 21:52 UTC close approach of 390725. Catalogue miss distance 77.6 LD · 2.98 × 10⁷ km. The curve is the geocentric path from 2036-05-15 to 2036-05-21, 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. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 77.6 LD · 2.98 × 10⁷ km 2036-05-18 21:52 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2036-05-18 21:52 UTC close approach of 390725. Catalogue miss distance 77.6 LD · 2.98 × 10⁷ km. The curve is the geocentric path from 2036-05-15 to 2036-05-21, 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. 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
2027-11-04 08:39:00 Venus 0.1384 AU 53.8 LD 19.3 km/s
2034-04-20 18:11:00 Venus 0.0907 AU 35.3 LD 16.2 km/s
2036-05-18 21:52:00 Earth 0.1994 AU 77.6 LD 18.8 km/s
2036-06-15 16:39:00 Venus 0.1261 AU 49.1 LD 18.4 km/s
2042-12-01 19:18:00 Venus 0.0935 AU 36.4 LD 16.7 km/s
2043-05-27 00:57:00 Earth 0.0974 AU 37.9 LD 11.8 km/s
2045-01-25 21:26:00 Venus 0.1177 AU 45.8 LD 17.7 km/s
2051-07-15 11:46:00 Venus 0.103 AU 40.1 LD 17.7 km/s
2053-09-07 07:57:00 Venus 0.1075 AU 41.8 LD 16.5 km/s
2054-05-22 14:39:00 Earth 0.1168 AU 45.4 LD 16.4 km/s

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

Sources