20 Massalia facts for kids
| Discovery | |
|---|---|
| Discovered by | Annibale de Gasparis |
| Discovery date | September 19, 1852 |
| Designations | |
| none | |
| Main belt (Massalia family) | |
| Orbital characteristics | |
| Epoch October 22, 2004 (JD 2453300.5) | |
| Aphelion | 411.911 Gm (2.753 AU) |
| Perihelion | 308.699 Gm (2.064 AU) |
| 360.305 Gm (2.408 AU) | |
| Eccentricity | 0.143 |
| 1365.261 d (3.74 a) | |
|
Average orbital speed
|
19.09 km/s |
| 161.641° | |
| Inclination | 0.707° |
| 206.530° | |
| 255.578° | |
| Physical characteristics | |
| Dimensions | 160×145×130 km |
| Mass | 5.2×1018 kg |
|
Mean density
|
3.2 g/cm³ |
| 0.054 m/s² | |
| 0.093 km/s | |
| 0.3374 d (8.098 h) | |
| Albedo | 0.210 (geometric) |
| Temperature | ~174 K max: 265 K (-8°C) |
|
Spectral type
|
S |
| 8.3 to 12.0 | |
| 6.50 | |
| 0.186" to 0.058" | |
20 Massalia is a large and bright asteroid found in the main asteroid belt. It is the biggest member of a group of space rocks called the Massalia family.
Contents
What is 20 Massalia?
Massalia is known as an S-type asteroid. This means it is mostly made of stony materials, like silicate rocks. It travels around the Sun in the middle part of the main asteroid belt. Its path is quite flat compared to Earth's orbit.
The Massalia Family
Massalia is by far the largest asteroid in its family. The other, smaller members of the Massalia family are thought to be pieces that broke off from Massalia. This likely happened during a huge impact event on Massalia's surface.
How Solid is Massalia?
Massalia is quite dense for an S-type asteroid. Its density is similar to that of solid rock. This suggests that Massalia is a strong, unbroken body. This is unusual for asteroids of its size. Many asteroids of similar size are often fractured or broken inside. Only a few very large asteroids, like 1 Ceres and 4 Vesta, are known to be solid.
Massalia's Shape and Spin
Scientists study how Massalia's brightness changes as it spins. This helps them figure out its shape and how it tilts. Massalia's pole (its axis of rotation) points towards certain directions in space. This means it has an axial tilt of about 45 degrees. Its shape is mostly round, but it has some flat or indented areas on its surface.
How Was Massalia Discovered?
Massalia was first spotted by Annibale de Gasparis on September 19, 1852. The very next night, Jean Chacornac also found it independently. However, it was Chacornac's discovery that was announced to the world first.
The name Massalia comes from the Greek name for the city of Marseille. This is the city in France where Chacornac made his discovery. De Gasparis, on the other hand, was observing from Naples, Italy.
