Transcript Relative sizes of astronomical objects

This is a representation of Earth relative to the rocky inner
planets and the outermost dwarf planet Pluto.
Note the difference in size between the gas giants (Jupiter, Saturn, Uranus
& Neptune) and the rocky inner planets (Mercury, Venus, Earth & Mars)
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Viewed in comparison to the Sun, Earth dwindles to a speck. Our sun is classified
as an unremarkable yellow dwarf main sequence star – one of over 100 million
such stars in our galaxy. However, it alone accounts for 99.9% of the mass of our
solar system, including all the planets, satellites (moons), asteroids, and
interplanetary debris.
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When compared it to some other stars, our Sun dwindles to the size of a corn kernel.
This image represents the relative sizes of our Sun and Sirius (Alpha Canis Majoris),
Pollux (Beta Geminorum) and Arcturus (Alpha Bootes). ‘Giant’ Jupiter is just 1 pixel in
this perspective. Earth is invisible on this scale.
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In this comparison our Sun is down to 1 pixel, a mote of dust with an arrow
pointing to it. Jupiter is invisible. Betelgeuse (Alpha Orionis) is a red
supergiant. If Betelgeuse replaced our Sun, its surface would lie between
the orbit of Mars and Jupiter. Antares (Alpha Scorpii) is a red supergiant 700
times the diameter of our Sun. The three stars noted below Antares are
Sirius, Pollux and Arcturus.
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VY Canis Majoris in the constellation Canis Major is a red hypergiant, the
largest known star. It is between 1,800–2,100 times the diameter of the
Sun. Placed at the center of our solar system, its diameter would extend out
slightly beyond the orbit of Saturn.
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And yet these are but just a few of the thousands of millions of stars in the
Milky Way! To comprehend the cosmic significance of our galaxy ...
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We finally turn to this Hubble Ultra-Deep Field image, a composite of pictures
taken in the constellation Fornax, September 2003-January 2004. The image
covers just 11.0 square arcminutes, smaller than a 1 mm-by-1 mm square of
paper held 1 meter away. Yet each one of those smudges is a galaxy. Some
10,000 of them have been counted in this image alone.