Can Pluto be seen at night without a telescope?

Answer 1

Think of a moth flying around a street-light, and you're standing 1/2 mile away

trying to see it. It's so small, and always so close to the bright light, that it's

tough for you to pick it out of the glare.

Mercury isn't much bigger than Earth's moon, and its orbit is the smallest of the

known planets. From where we are, it always appears so close to the sun that

it never rises until just a short time before the sun, and it always sets just a

short time after the sun. It's tiny, and it's never up when the sky is good and

dark, so it's always tough to pick it out of the sun's glare.

Answer 2

Mercury is certainly bright enough to see without a telescope. The problem is its

position in the sky. It's never far from the sun, so it never rises much before the

sun, or sets much after it. I don't know how true it is, but I've heard it said that

Kepler never saw Mercury.

The answer to your question is: Mercury can't be seen at night at all. By the time

the sun is good and gone, so is Mercury.

Answer 3

not really, it's way to dim. At its closest to Earth, Neptune has a visual magnitude of 5, which is barely perceptible to the unaided eye under ideal conditions (really dark sky, really clear air, preferably at altitude). At the time of this answer, Neptune's visual magnitude is more like +8, which requires at least a good pair of binoculars.

Answer 4

Neptune is now about one month ahead of Uranus, best visible in the evening sky from August through October. The two planets are near-twins in actual size, but Neptune is about 50% more distant, which makes it surprisingly much harder to find. But if you can find Uranus, you can find Neptune too, with the aid of the charts below. It just requires using the same techniques more carefully.

Neptune varies from magnitude 7.8 to 8.0, about two magnitudes fainter than Uranus. It's visible in steadily-supported binoculars, but only if you look quite carefully. And while Uranus is frequently brighter than any other star visible in the same binocular or finderscope field, the sky is crowded full of stars as bright as Neptune. So you have to be careful when you match up your charts with what you see through the eyepiece.

Having said all that, it's worth remembering that even a very small telescope can easily show stars down to eighth or ninth magnitude. So Neptune is not faint by telescopic standards. In fact, it's bright enough to stimulate color vision through any telescope with 4 inches (100 mm) of aperture. Look for a hue quite similar to Uranus's, though somewhat bluer.

Neptune's disk is plainly visible at 200× through a 6-inch telescope on a night of steady seeing. But it may be quite hard to see the disk if conditions are bad or your telescope is improperly collimated. My 70-mm refractor is a little too small to resolve Neptune properly, but if I examine the planet carefully at 120× it looks clearly different from a star of similar brightness. Neptune's light is distinctly steadier, and it appears more solid. Not exactly a disk, but a fat pinpoint. But don't take my word for it; see for yourself what Neptune looks like!

Answer 5

If you know where to look, you can see six planets for sure, and possibly a seventh,

without a telescope. Mercury is not dim or far away, but it's difficult, because it's

always near the sun in the sky. So it either sets shortly after the sun, or rises shortly

before the sun, and is never very high in the sky when the sun is not also up.

Answer 6

No. The limit of naked eye visibility is usually taken to be magnitude 6.5, and the brightest Neptune ever gets is about magnitude 7.8 (on the magnitude scale, lower is brighter).

Or, maybe ... yes, if you don't count binoculars as a "telescope". A decent pair of binoculars provides enough light amplification to see things around tenth magnitude.

Answer 7

Yes, on the dark side.

Answer 8

yes

Answer 9

no