Large changes in Pluto's atmosphere as revealed by recent stellar occultations.
Pluto's tenuous nitrogen atmosphere was first detected by the imprint left on the light curve of a star that was occulted by the planet in 1985 (ref. 1), and studied more extensively during a second occultation event in 1988 (refs 2-6). These events are, however, quite rare and Pluto's atmosphere remains poorly understood, as in particular the planet has not yet been visited by a spacecraft. Here we report data from the first occultations by Pluto since 1988. We find that, during the intervening 14 years, there seems to have been a doubling of the atmospheric pressure, a probable seasonal effect on Pluto.
Sicardy
B
B
Observatoire de Paris, LESIA, 92195 Meudon, France. bruno.sicardy@obspm.fr
Widemann
T
T
Lellouch
E
E
Veillet
C
C
Cuillandre
J-C
JC
Colas
F
F
Roques
F
F
Beisker
W
W
Kretlow
M
M
Lagrange
A-M
AM
Gendron
E
E
Lacombe
F
F
Lecacheux
J
J
Birnbaum
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C
Fienga
A
A
Leyrat
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C
Maury
A
A
Raynaud
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E
Renner
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S
Schultheis
M
M
Brooks
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Delsanti
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A
Hainaut
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Gilmozzi
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R
Lidman
C
C
Spyromilio
J
J
Rapaport
M
M
Rosenzweig
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P
Naranjo
O
O
Porras
L
L
Díaz
F
F
Calderón
H
H
Carrillo
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Carvajal
A
A
Recalde
E
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Cavero
L Gaviria
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Montalvo
C
C
Barría
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D
Campos
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R
Duffard
R
R
Levato
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