Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty
The Bruce Murray Space Image Library

Alice solar occultation

Filed under New Horizons, pretty pictures, Pluto

Go Back

Alice solar occultation This figure shows how the Alice instrument count rate changed over time during the sunset and sunrise observations. The count rate is largest when the line of sight to the sun is outside of the atmosphere at the start and end times. Molecular nitrogen (N2) starts absorbing sunlight in the upper reaches of Pluto’s atmosphere, decreasing as the spacecraft approaches the planet’s shadow. As the occultation progresses, atmospheric methane and hydrocarbons can also absorb the sunlight and further decrease the count rate. When the spacecraft is totally in Pluto’s shadow the count rate goes to zero. As the spacecraft emerges from Pluto’s shadow into sunrise, the process is reversed. By plotting the observed count rate in the reverse time direction, it is seen that the atmospheres on opposite sides of Pluto are nearly identical.


Original image data dated on or about July 15, 2015.

Most NASA images are in the public domain. Reuse of this image is governed by NASA's image use policy.


Other Related Images


Leave a Comment:

You must be logged in to submit a comment. Log in now.

Space in Images

Pretty pictures and
awe-inspiring science.

See More

Join The Planetary Society

Let’s explore the cosmos together!

Become a Member

Connect With Us

Facebook, Twitter, YouTube and more…
Continue the conversation with our online community!