Freaky Fzx Friday - Finding Exoplanets -

I graduated from high school in 1988 without a single confirmed exoplanet discovery.  Today, according to Jet Propulsion Laboratory, we count 5,003 planets of other suns and have independently confirmed 1,804.  Science has changed and keeps changing so check the link.

"Planet Quest" and the "Exoplanet Travel Bureau" seem like science fiction but clicking on the link takes you to the "Exoplanet Travel Series" which helps you make sense of such things as planets of twin suns, super-earth gravity, and different possible colors for alien plant life.  Interesting.

Tatooine is real

It is impossible, however, to actually see even a single exoplanet using the best telescope that we have.  So how do we detect them?

Sometimes digital pictures are taken using various wavelengths of electromagnetic energy and then analyzed.  It can take years to determine the presence of an exoplanet of a star from those images.  It is a difficult method and few exoplanets can be resolved from their stars, but it's possible using some ground-based telescopes and satellite telescopes.

Imaging an exoplanet

Part of the problem with astronomy has always been our atmosphere.  Look at a star and you'll see it twinkle with simple naked eye observations.  The fluctuations you see are the atomospheric influences on light from the star.  If we can see it with our puny unmagnified eyes it's got to be worse for a telescope.  Most of the exoplanets 'discovered' from the 1800s to the mid 1900s have been proven false and attributed to atmospheric aberrations.

So we put our best telescopes in space to avoid atmospheric image distortion.  But sometimes our satellite telescopes can't even focus properly until years later due to spherical aberration.  Silly mistakes.

     

The Hubble Telescope had problems at first

We can also compensate for atmospheric wavering using adaptive optics.

A large planet will cause a wobble in the sun.  If the wobble is along a line of sight from the earth, it's detectable using the spectral doppler shift.

A large planet passing in front of a star will cause a temporary drop in brightness that can be measured to help determine its size.

Earth affects the motion of the sun - it wobbles.  Pulsars change their emission frequency ever so slightly if they have planets.  Binary stars orbit each other and if aligned so we can see an eclipse, those eclipses will time-vary based on the orbit of any planets in the system.

Here are videos to help us understand a tiny bit more about the process.

False positives are a common problem so we have to confirm the existence of the exoplanet before we count it in the total.  We have found that planets around other suns are common but we continue to wonder if any of are really habitable by people like us.  Stay tuned and keep on checking that link for more exoplanet news.