In 2020, the dazzlingly brilliant Jupiter and the exceedingly faint Pluto remain close together throughout the year, cuddling up in front of the constellation Sagittarius. Pluto can only be viewed using a telescope. Throughout 2020, dazzling Jupiter allows us to imagine Pluto with our minds' eye on the dome of the sky.
Pluto is a dwarf planet that was considered to be a planet itself until 2015 when it was demoted to a dwarf planet. Founded in 2003, Pluto meets all the requirements to be called a planet except it's orbit is too elliptical to be considered circular. It takes Plutonian years for Pluto to go around the Sun once.
It's estimated that there are more than 9 million galaxies in the Universe. Only one of these contains Earth-like planets, so we might as well enjoy what little time we have here.
The galaxy we call home is called Milky Way. It has a diameter of 300-400 thousand light years and consists of approximately 400 billion stars with a mass of about 500 billion solar masses. If you zoom into Milky Way you'll see hundreds of billions of stars. Even though we're not alone in the universe, it's very big and empty.
The brightest object in the night sky is Venus, which always appears as a morning star just before dawn.
Despite the fact that Jupiter and Pluto nearly align along the same line of sight throughout 2020, these two worlds are not close in space. Jupiter is little more than 5 astronomical units (AU) from the sun, but Pluto lies far beyond Jupiter, in the Kuiper Belt, at more than 34 AU.
Jupiter and Pluto cross paths every 360 days, but because Jupiter is so much bigger than Pluto, its orbit is not affected much by their gravitational pull. If anything, Jupiter's gravity makes Pluto orbit the sun faster than it would otherwise, but this effect is very small — only about 1 millimeter per year faster than if they were not connected.
These objects are all gas giants, with Pluto being the only one that has a solid surface. The other three planets in our solar system: Jupiter, Saturn, and Neptune. All are very important factors when it comes to understanding how planets are formed and why some turn out to be rockier or gassier than others.
Pluto was originally considered a planet until 2015, when scientists voted to remove it from the list because it does not meet the requirements for being called a planet. Now it is classified as a dwarf planet because it doesn't reach the mass threshold necessary to be listed as a planet under most definitions.
Dwarf planets are known as such because they are less massive than stars but more than rocks.
Pluto is currently in the constellation Sagittarius, which is visible from mid-northern latitudes (this includes observers in the US). And, after rising in the east after sunset, it will proceed south, keeping low to the horizon. It's difficult to see Pluto, but it's even more difficult to get there. The closest approach Earth will make to Pluto is about 38000 miles (62000 km), and that will happen on July 14th.
From our location, it's estimated that only 0.6% of Pluto is illuminated by the sun. So, despite its distance from us, it's still too bright to look at directly. Instead, we need a telescope.
In addition to being visible with the naked eye, Jupiter, Saturn, Uranus and Neptune are also visible to the naked eye as twilight stars. They don't remain visible after darkness falls because they're so far away from us. But you can see them if you go outside when it's dark out and look up at the sky.
Mars is also sometimes seen in the night sky. It won't be visible this year because it's inside Earth's orbit and thus never rises above the western horizon. But if you go outside when it's dark out and scan the skies above you, you should be able to find it.
Visible planets include Jupiter, Saturn, Uranus and Neptune.
First, you'll need a very large telescope, preferably one with at least a 10-inch diameter, because Pluto is now at magnitude 14.0, making it appear quite dark in the sky. 3AO Telescope Finder can help you select the right telescope for viewing such distant objects as Pluto and Neptune.
Next, you need to understand how magnifications work. The closer an object is to you, the brighter it appears. So if I were looking at Pluto with my unaided eye, it would be too dim to see. But using a microscope, I could see details on its surface that are invisible to the naked eye. A microscope allows me to make Pluto look more like Earth than my unaided eye does.
Finally, you need to know how far away Pluto is. It's so far away that even with a telescope you wouldn't be able to see any detail on its surface. But since we're talking about a microscope here, let's say that it's located in New York City. Using my website's astronomical calculator, I can figure out that Pluto is 86400 miles from Earth, which means that its image on the Moon would be about half-full. This is why astronomers call Pluto and other Kuiper belt objects dwarf planets; they're not stars but rather icy rocks in another part of our Solar System.
Is there no telescope? To discover star parties and/or astronomy groups near you, use NASA's Night Sky Network. You don't even need a telescope to exercise your imagination. Star charts, photos, and videos help you feel like you're out there, too.
For those who have never seen it before, here are the four major types of objects that can be found in the night sky: Stars, galaxies, nebulae, and planets. Planets include Earth and its moon, but also other bodies such as Mars or Jupiter's moon, Metis. Nebulae are large clouds of gas that emit light of their own or reflect light from surrounding objects. Stars are the energy sources for all living things; they emit light over a wide range of wavelengths, from gamma rays to infrared. Galaxies are large collections of stars and interstellar gas that appear in the night sky as luminous objects. A galaxy cluster is a large grouping of such objects.
The Moon is often called "the Earth's sister planet" because both are members of the Solar System. But while Earth's sister planet Venus is always cloudy, the Moon is always visible in some form or another. Even during daytime, sunlight refracts through Earth's atmosphere to create beautiful sunsets!
Second, you'll need a detailed map of the stars through which Pluto is traveling. The finest printed star atlases only go down to the 11th magnitude, which is insufficiently dim. So to see every detail of Pluto's orbit, you'll need a computerized map of deeper space.
Third, you'll need to be able to observe from a location where there is no light pollution. This means a dark site free from obstacles such as trees or buildings. Finally, you'll need to wait about 7 years for Pluto to make its next close approach to Earth!
On June 25, 2015, astronomers using telescopes across the world will watch as Pluto makes its closest approach to Earth since 1930, when it was first discovered. From this distance, objects as far away as Pluto are visible with the naked eye under ideal conditions. In fact, with the exception of the Moon, nothing else is closer than Pluto during the nighttime hours.
The best place to see it is from within a city with low or no light pollution, such as Albuquerque, New Mexico; Banff, Alberta, Canada; or Svalbard, Norway. You may even see a few stars with your favorite telescope!
Pluto has two natural satellites, Charon and Nix, which are both larger than our Moon.