3 ms·
One thing to keep in mind is that there is one thing that happens with exoplanets that can never happen with Pluto: the planet can pass between its star and us
by peeters 11y ago
One thing to keep in mind is that there is one thing that happens with exoplanets that can never happen with Pluto: the planet can pass between its star and us (i.e. eclipse the star). This gives a lot of information about the planet's composition, because light from the star will scatter/change color according to the planet's composition. See this image: http://seagerexoplanets.mit.edu/images/transitschematic.gif http://seagerexoplanets.mit.edu/images/transitschematic.gif.
Now maybe you can do that with Pluto using some far-off star for reference, not sure. Also, I'm not sure if in this specific example the exoplanet made a transit of its star, or if it was detected by other means (usually by measuring its gravitational affect on the star, i.e. its star "wobbles").
- privong 11y ago> Now maybe you can do that with Pluto using some far-off star for reference, not sure. It has been done for Pluto, first in 1988, with an occultation of a background star[0]. [0] http://www.space.com/29885-pluto-atmosphere-to-be-revealed-by-nasa-new-horizons-spacecraft.html http://www.space.com/29885-pluto-atmosphere-to-be-revealed-b...
- goodcanadian 11y agoAnd most recently with SOFIA at the end of June: https://sofia.usra.edu/News/news_2015/06_29_15/index.html https://sofia.usra.edu/News/news_2015/06_29_15/index.html This will help tie in past and future occultation observations to the New Horizons data.
- dr_zoidberg 11y agoAs I understand, star transits by Pluto helped to better estimate its size before NH. But as you said, it's complicated to get a full spectrographic analisys of its atmosphere this way. Kepler is a mission that mostly works with photometric measurements of planet transits in front of their stars.
- Sharlin 11y agoAnd indeed the fact that the observed transits were "fuzzy" told us that Pluto has a (very tenuous) atmosphere. Indeed, Pluto's diameter had considerable uncertainty before New Horizons arrived due to this (unlike Charon's whose transits were always tack sharp.)
- verytrivial 11y agoIndeed this is exactly what New Horizons did very recently. After shooting past Pluto, the probe spun around to view it with the sun behind it. http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?gallery_id=2&image_id=238 http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?...