Astronomy/Solar System


How large is the Solar System?

Our solar system is very large.  Let's take a basketball (which is about 24 cm in diameter) to represent the Sun.  If the Sun is a basketball, then the Earth would be about 2.5 meters away.  Going out further, Neptune would be 775 meters away while Pluto would be 1.3 kilometers away! So you can see Pluto is much further away than the 8 planets.  However, if you want to continue all the way to the Oort Cloud, where we think the comets live, that would be over 130 kilometers away!  In comparison, our closest neighbour star, Alpha Centauri, would be 7,160 kilometers away!



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Brad Tucker


I'm happy to answer any general questions about Astronomy, Astrophysics, and Cosmology. I'm also happy to take general, specific, and detailed questions related to supernovae, Baryonic Acoustic Oscillations, the Cosmic Microwave Background, dark matter, dark energy, and the Big Bang Theory. I'm also happy to chat about Astronomy/Astrophysics education and careers, and philosophy and science.


I am a professional research astronomer/astrophysicist/cosmologist. My research focuses on studying supernovae and using them to measure the properties of the Universe, such as how fast it is growing and what it is made of. I also frequently give talks to school groups and the public, and am a regular guest on various radio stations.

Current Research Fellow at Mt. Stromlo Observatory, the Australian National University, and in the Department of Astronomy, University of California, Berkeley.

Lots of journals, including the Astrophysical Journal, the Astronomical Journal, and Nature. I am currently in the middle of writing my first popular book.

B.A. Philosophy, University of Notre Dame, Notre Dame, IN USA B.A. Theology, University of Notre Dame, Notre Dame, IN USA B.Sc. Physics, University of Notre Dame, Notre Dame, IN USA Ph.D. Astrophysics, Mt. Stromlo Observatory, the Australian National University, Canberra, ACT, Australia

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