2021

Orbit of Asteroid 99942 Apophis 2021

Orbital elements listed here are taken from the JPL Horizons website, and represent the current best solution. The orbit will only be perturbed slightly during the close approach to the Earth, but we still provide the Keplerian elements for both the pre- and post-Earth encounter.

Orbital Elements (Solution JPL#199)

Epoch 2459279.54166 2021-Mar-06.0
Perihelion Time T = 2021-Jul-29 02:26:34 UT
Perihelion Time (JD) T = 2459424.601782
Orbital Period P = 0.8859 yr
Semi-major Axis a = 0.9224 au
Perihelion Distance q = 0.7457 AU
Eccentricity e = 0.1916
Inclination (J2000) i = 3.34°
Ascending Node (J2000) Ω = 203.99°
Argument of Perihelion (J2000) ω = 126.66°
Perigee Time t = 2021-Mar-06 01:06 UT
Perigee Distance Δ = 0.1126 AU
Δ = 1.685×107 km
Velocity with respect to Earth
at closest approach
4.658 km/s
Min. Orbital Intersection Dist. MOID = 0.0003156 AU

Full Orbit From Above

View of Asteroid 99942 Apophis 2021's pre-encounter orbit as seen from the North ecliptic pole with the asteroid and planets shown at the time of the asteroid's closest approach to Earth. From the JPL Small-Body Database Browser.

View of Apophis' entire orbit.


Orbit in Oblique View

Oblique view of the portion of Asteroid 99942 Apophis 2021's orbit around perigee, viewed from 30° above the ecliptic plane. The black dot denotes the asteroid's and Earth's positions at perigee (2019-May-25).
Oblique view of Apophis' orbit.
PDF Version

Orbit in Earth Co-Orbital View

The orbit of Asteroid 99942 Apophis 2021 around perihelion, in the Earth's co-orbital reference frame, as seen from above (top panel) and in the ecliptic plane (bottom panel). The black circle denotes the asteroid's position at perihelion (2019-Mar-22) and the open circles show positions at 30-day intervals.
Plot of Apophis' orbit in Earth-co-orbital frame.
PDF Version

2027

Orbit of Asteroid 99942 Apophis 2027

example parametersOrbital elements listed below are taken from the JPL Horizons website, and represent the current best solution. The orbit will only be perturbed slightly during the close approach to the Earth, but we still provide the Keplerian elements for both the pre- and post-Earth encounter.

Orbital Elements (Solution JPL#218)

Epoch 2460600.5 2024-Oct-17.0
Perihelion Time T = 2025-Feb-12.85355952 TDB
Perihelion Time (JD) T = 2460719.353559523448
Orbital Period P = 0.88588 yr
Semi-major Axis a = 0.92238 au
Perihelion Distance q = 0.74607 AU
Eccentricity e = 0.19115
Inclination (J2000) i = 3.34°
Ascending Node (J2000) Ω = 203.904°
Argument of Perihelion (J2000) ω = 126.672°
Perigee Time t = ??
Perigee Distance Δ = ?? AU
Δ = ??×107 km
Velocity with respect to Earth
at closest approach
?? km/s
Min. Orbital Intersection Dist. MOID = 0.?? AU

Full Orbit From Above

View of Asteroid 99942 Apophis 2027's pre-encounter orbit as seen from the North ecliptic pole with the asteroid and planets shown at the time of the asteroid's closest approach to Earth. From the JPL Small-Body Database Browser.

View of Apophis' entire orbit.


Orbit in Oblique View

Oblique view of the portion of Asteroid 99942 Apophis 2027's orbit around perigee, viewed from 30° above the ecliptic plane. The black dot denotes the asteroid's and Earth's positions at perigee (2019-May-25).
Oblique view of Apophis' orbit.
PDF Version

Orbit in Earth Co-Orbital View

The orbit of Asteroid 99942 Apophis 2027 around perihelion, in the Earth's co-orbital reference frame, as seen from above (top panel) and in the ecliptic plane (bottom panel). The black circle denotes the asteroid's position at perihelion (2019-Mar-22) and the open circles show positions at 30-day intervals.
Plot of Apophis' orbit in Earth-co-orbital frame.
PDF Version

2028

2029