ASPERA-3 on Mars Express
One year on orbit
Stas Barabash
Swedish Institute of Space Physics, Kiruna, Sweden
and
the ASPERA-3 team
1
Stas Barabash, ASPERA-3
The planetary wind
Solar
wind
Planetary wind
≈100 ton/day
Solar wind is blowing away planetary ions and planetary
materials!
2
Stas Barabash, ASPERA-3
The planetary wind. High speed!
Solar
wind
Planetary wind
≈ 400 km/s
• The solar wind penetrates deep down into the dayside
atmosphere
• Planetary heavy ions accelerated up to very high
energies!
3
Stas Barabash, ASPERA-3
The planetary wind. Escaping Atomic O and O2
Solar
wind
Planetary wind
O+, O+2 , CO+, CO+2
• The planetary wind is dominated by atomic- and
molecular oxygen.
• Carbon dioxide escapes too!
• Did water escape this way?
4
Stas Barabash, ASPERA-3
For the first time we see Mars ”radiates” fast
atoms!
Energetic Neutral
Hydrogen Atoms
Solar Wind
5
Stas Barabash, ASPERA-3
ASPERA-3 result
The interplanetary medium is important to
understand Martian atmosphere evolution!
Solar wind
6
Stas Barabash, ASPERA-3
Planetary wind
≈100 ton/day