Guide to the Solar System and Deep Sky Objects - Astronoscope

Guide to The Solar System and Deep Sky Objects

In this section we want to give you some basic information about the planets of our Solar system and some of the easier to locate and view Deep Sky objects.

There are a number of very good, free online resources that will tell you what stars, planets, nebulae and galaxies are visible from your location on any given night. Our favourite is:

Stellarium- windows OS, mac OS and browser accessibility. Mobile phone app also available

Solar System Planets, Dwarfs and Moons

The easiest and probably the first targets for those new to Astronomy. The planets, Mercury, Venus, Mars, Jupiter and Saturn are all visible to the naked eye, the others Uranus, Neptune and Pluto require binoculars or telescopes.

The Moon

The most obvious body in our night sky. Best to use a lower magnification eyepiece if you want to see the whole body, particularly at full moon. A moon filter may also be used to reduce the glare of the moon’s reflected light.


The Sun 

Warning NEVER look directly at or near the Sun through an unfiltered Telescope or Binoculars as this will cause immediate and irreparable blindness.

Using appropriate filters, you can see details on the surface of the Sun like sunspots and prominences.


The smallest planet in the solar system and also the planet that orbits closest to the sun. It is a tricky planet to catch a glimpse because of the extreme proximity of the sun. At maximum elongation it can be viewed just after sunset or just before sunrise. Take caution not accidently catch the Sun's disc in your viewing instrument as this will cause severe damage to your eyes.


Often mistaken for a bright star, the planet Venus is often visible in the evening or early morning either just after the Sun sets or just before it rises. Again, be careful if scanning the sky for Venus through telescope or binoculars if the Sun is still visible.


The fourth and second smallest planet in the Solar system. Often referred to as the 'Red Planet', Mars can easily be seen from Earth with the naked eye, as can its reddish colouring. Its apparent Magnitude reaches −2.94, which is surpassed only by Venus, the Moon and the Sun. Binoculars or Telescopes will resolve some surface detail.


The largest planet in the Solar system, it is clearly visible to the naked eye. It's magnitude varies depending on it's position in relation to the Earth and Sun, but the mean value is -2.2, usually the fourth or fifth brightest object in the sky after the Sun, Moon, Venus and sometimes Mars. With Binoculars or a telescope it is possible to resolve the cloud bands, the 'Giant Red Spot' and even some of it's Moons.


The second largest planet in our Solar system, and most well known as the 'ringed planet'. It orbits between 9 and 10AU from the Sun, and takes almost 29.5 Earth years to orbit the Sun. Although it is visible to the naked eye, most people will require an optical aid (very large binoculars or a small telescope) that magnifies at least 30 times to achieve an image of Saturn's rings in which clear resolution is present.


Not visible to the naked eye from Earth. Uranus is the seventh planet from the Sun. It became the first planet discovered with the use of a telescope. Uranus is tipped over on its side with an axial tilt of 98 degrees. It is often described as “rolling around the Sun on its side.”


Neptune is the eighth planet from the Sun, making it the most distant in the solar system. This gas giant may have formed much closer to the Sun in the early solar system history before migrating out to its current position. It is not visible to the naked eye but can be seen with larger telescopes.



Now we look at objects in deep space that many people are familiar with, but may not know exactly where to find them.


A constellation visible during the winter months, famous for the ‘belt’ of three stars that also holds the Horsehead Nebula. The Picture below shows the belt with the Horsehead Nebula below the left most star, Alnitak.



Better known as the Seven Sisters, this is an open star cluster. The average distance is 444ly. It is a clear naked eye object during the winter months. You can use the three stars of Orion’s belt as a signpost to find the seven sisters.


Sirius is the brightest star in the night sky with an apparent magnitude of -1.46, it can be found using Orion’s belt again, but this time in the opposite direction than that shown above.

Summer Triangle

As the name suggests, during the northern summer months, three unrelated stars form an asterism as seen from Earth.  The stars, Vega, Deneb and Altair form a triangle formation that is easily visible to the naked eye.

Big Dipper

More properly known as Ursa Major, this constellation is visible year-round from the UK in the Northern sky.

Pole Star

More correctly called Polaris, this star almost exactly aligns with Earth’s Northern axial pole and therefore does not appear to move at all as the Earth rotates. It can easily be found using the outer two stars of Ursa Major as a signpost as demonstrated in this graphic. It has an apparent magnitude of 1.98 and is located at a distance of 432.57ly.

Great Square of Pegasus and M31 Andromeda Galaxy

The 'Great Square' is best viewed from the Northern Hemisphere during the late autumn and winter months. It's four main stars form a large square that is clearly visible to the naked eye. It also forms a handy signpost to find another galaxy!

The Andromeda Galaxy is currently about 2.5 million light years away, but will, in a few billion years, collide with our Milky Way. It is the furthest naked eye object currently visible in the night sky at magnitude of 3.4. It is best viewed from the northern hemisphere in the autumn and winter months, and is located above the Great Square of Pegasus. The upper left star of the Great Square (Alpheratz) can be used to locate Mirach and then M31 as shown below.

Graphics and images on this page courtesy of NASA/JPL/ESA and