The Solar System at your Fingertips
Dwarf Planets and Asteroids » 

Asteroid 99942 Apophis

Available Resources

Asteroid 99942 Apophis Sky Charts and Coordinates

This is a simplified sky chart, showing where Asteroid 99942 Apophis is now with respect to the brightest stars and constellations.

More advanced sky charts are available on TheSkyLive for this object: 1) the Online Planetarium which is interactive and allows to select dates and additional objects to visualize; and 2) the Live Position and Data Tracker which provides the highest precision position data and features deep sky imagery from the Digitized Sky Survey.

Asteroid 99942 Apophis in Capricornus on January, 22 2018
High Precision Live Sky Chart
21h 34m 29s
-13° 26’ 35”
21.15
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Asteroid 99942 Apophis Rise and Set Times

Today's Asteroid 99942 Apophis rise, transit and set times from Greenwich, United Kingdom [change]. All times are relative to the local timezone Europe/London.

Azimuth: 103.4°
Max altitude: 25.1°
Azimuth: 256.6°

Asteroid 99942 Apophis Orbit Diagram

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Asteroid 99942 Apophis with respect of the Sun and the orbits of the major planets. The position of Asteroid 99942 Apophis and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Orbit Diagram of Asteroid 99942 Apophis
View Asteroid 99942 Apophis in the 3D Solar System Simulator

Asteroid 99942 Apophis Ephemeris

The following table lists the ephemerides of Asteroid 99942 Apophis computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Asteroid 99942 Apophis in our Online Planetarium at the chosen date.

Date MagnitudeMag Right AscensionR.A. DeclinationDec. Constellation
2018 Jan 15 21.10 20h 58m 23s -15° 58’ 05” Capricornus
2018 Jan 16 21.11 21h 03m 35s -15° 37’ 44” Capricornus
2018 Jan 17 21.11 21h 08m 48s -15° 16’ 54” Capricornus
2018 Jan 18 21.12 21h 13m 58s -14° 55’ 39” Capricornus
2018 Jan 19 21.13 21h 19m 08s -14° 33’ 57” Capricornus
2018 Jan 20 21.14 21h 24m 15s -14° 11’ 53” Aquarius
2018 Jan 21 21.14 21h 29m 23s -13° 49’ 26” Capricornus
2018 Jan 22 21.15 21h 34m 29s -13° 26’ 35” Capricornus
2018 Jan 23 21.16 21h 39m 36s -13° 03’ 23” Capricornus
2018 Jan 24 21.17 21h 44m 39s -12° 39’ 50” Capricornus
2018 Jan 25 21.18 21h 49m 42s -12° 15’ 57” Capricornus
2018 Jan 26 21.19 21h 54m 46s -11° 51’ 47” Capricornus
2018 Jan 27 21.20 21h 59m 47s -11° 27’ 18” Aquarius
2018 Jan 28 21.21 22h 04m 46s -11° 02’ 30” Aquarius

Distance of Asteroid 99942 Apophis from Earth

The following chart shows the distance of Asteroid 99942 Apophis from Earth as a function of time. Distance data is measured in Astronomical Units and sampled with a 2 days interval.

The reported distances might be inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of 99942 Apophis is also available as a real time updated value in the Live Position and Data Tracker.

Distance of Asteroid 99942 Apophis from Earth between January 2013 and December 2075

Light Curve of Asteroid 99942 Apophis

The following chart is the predicted light curve (visual magnitude as a function of time) of Asteroid 99942 Apophis, according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.

Predicted magnitude of Asteroid 99942 Apophis between January 2013 and December 2075

Asteroid 99942 Apophis Physical Data

The following shows the known values of the most important physical parameters of Asteroid 99942 Apophis. Source: JPL Small-Body Database

Physical Parameter Value Relative to Earth
Diameter 0.325 km 0.0000
Sideral Rotation 30.4000 hours 1.2701
Absolute Magnitude 19.7
Geometric Albedo 0.23

Asteroid 99942 Apophis Orbital Elements

The following table lists the orbital elements of Asteroid 99942 Apophis at epoch 23 September 2008 00:00 UTC (JD: 2454733.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.19119530
Orbit inclination i 3.33136952°
Perihelion distance q 0.74607243 AU
111,610,847 km
Aphelion distance Q 1.09880417 AU
164,378,765 km
Semi-major axis a 0.92243830 AU
137,994,806 km
Orbital period period 0.8900 years
323.5969 days
Date of perihelion transit Tp 2009-Mar-04 09:54:01
2,454,894.9125 JD
Next perihelion transit 2010-Jan-22 00:13
2,455,218.5095 JD
Argument of perihelion peri 126.40187952485°
Longitude of the ascending node node 204.44602891898°
Mean anomaly M 180.42937304564°
Mean motion n 1.11249504°/day
Closest approach to Earth* 2029-Apr-14
Distance of closest approach* 0.00043719 AU
65,403 km

* NOTE: values for the closest approach are computed for the time interval between 2013-Jan-01 and 2075-Dec-31, with a sampling interval of 1 day.