Seeing the Solar System

   To find the planets, you'll need to know where to look. Refer to Sky & Telescope or a similar magazine for up to date positions or check one of the several Web sites that show planetary positions. A planetarium program (such as Starry Night for the Mac or SkyMap for PCs) can also be useful, especially for the moons.

   The tables below are ordered by visual magnitude ("Vo"; bigger numbers are dimmer); this is the maximum brightness that the object attains (approximately when it is closest to Earth). "Date" is the date of discovery.

 

Unaided Eye

You can see 99.99% of the mass of the solar system with no instruments whatsoever.

Name	Vo
Sun	-27
Earth
Moon	-13
Venus	-4.4
Jupiter	-2.7
Mars	-2.0
Mercury	-1.9
Saturn	+0.7

Notes:

• Never look directly at the Sun!
• Those with good eyes (especially children) and dark skies may be able to see a few of the objects below, too.
• Does the Earth really count? Only the Apollo astronauts have ever seen the Earth from far enough away to perceive it as a globe.

 

Binoculars

A simple pair of binoculars is by far the most cost-effective optical aid available. For $200 you can get a far better optical instrument than Galileo or Newton had. You will find it much easier if you arrange a stable support for your binoculars (such as a tripod).

Name	Date	Vo	Discoverer
Ganymede	1610	4.6	Galileo Galilei
Io	1610	5.0	Galileo Galilei
Europa	1610	5.3	Galileo Galilei
Uranus	1781	5.5	William Herschel
Callisto	1610	5.6	Galileo Galilei
Neptune	1846	7.8	Johann Gotfried Galle
Titan	1655	8.3	Christiaan Huygens

 

Amateur Telescopes

If you're really serious a modest telescope will reveal many more moons. The first few below are pretty easy, the last few are considerably more difficult. Good dark skies are essential.

Name	Date	Vo	Discoverer
Rhea	1672	9.7	Giovanni Domenico Cassini
Tethys	1684	10.2	Giovanni Domenico Cassini
Iapetus	1671	10.2	Giovanni Domenico Cassini
Dione	1684	10.4	Giovanni Domenico Cassini
Phobos	1877	11.3	Asaph Hall
Enceladus	1789	11.7	William Herschel
Deimos	1877	12.4	Asaph Hall
Mimas	1789	12.9	William Herschel
Triton	1846	13.5	William Lassell
Pluto	1930	13.6	Clyde W. Tombaugh
Titania	1787	13.7	William Herschel
Oberon	1787	13.9	William Herschel
Amalthea	1892	14.1	Edward Emerson Barnard
Ariel	1851	14.2	William Lassell
Hyperion	1848	14.2	William Cranch Bond
Janus	1966	14.5	Audouin Dollfus
Umbriel	1851	14.8	William Lassell
Himalia	1904	14.8	C. Perrine

Notes:

• Phobos and Deimos are harder to see than it might appear since they are so close to Mars (and the above magnitudes are at for a favorable opposition)
• The same holds for Amalthea and Janus.
• Iapetus' brightness varies greatly as it rotates, from 10.2 to 11.9 or less.
• The order of discovery may be a better guide to what is easy to see than magnitude.

 

Other objects

   Of course, the solar system has more than just planets and moons. Every year there are comets that can be seen with small telescopes and usually one or two that can be seen with binoculars. Occasionally there are naked-eye comets; there will be at least one in 1996 (Hyakutake) and another (Hale-Bopp) in 1997.

   Its easy to see a few of the brighter asteroids with binoculars. Several hundred can be seen with small telescopes.

   If you're out at night under a clear sky, you are pretty likely to see a meteor. You may see dozens of meteors if you catch one of the regular meteor showers.

   You can even see the interplanetary medium if you're close enough to the poles to see an aurora or if you see the zodical light or the gegenschein.

   You can also see the stars 51 Pegasi, 70 Virginis and 47 Ursae Majoris which probably have their own planets, though of course, you can't see the planets themselves.

Pictures

(taken with amateur telescopes)

• Venus at noon (Mel Bartels) 8k jpg

   

• 2 images of Mars (Dean W. Armstrong) html

   

• Jupiter (Dean W. Armstrong) 15k jpg

   

• Saturn (D. Armstrong) 9k jpg

   

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