Are you an avid stargazer? If so, you probably want to know when you can see not just the stars but the visible planets in our Solar System as well. These are sometimes referred to as the “naked-eye planets,” because you can see them with the naked eye—no telescope or binoculars needed (except for Neptune!). This handy guide gives you the dates for when you can see the planets throughout the year. This is one page you’ll want to bookmark!
When You Can See The Planets in 2021
Mercury is the closest planet to the Sun in our Solar System. Because it is so close to the Sun, it is only observable in the early morning, just after sunrise, or at dusk. In fact, ancient Greek astronomers once believed Mercury was actually two separate objects. It usually appears as a bright “star” with a golden hue. As an evening star, appears in the western sky setting about an hour after the Sun; as a morning star, it appears in the eastern sky rising about an hour before the Sun.
When Is Mercury Visible in 2021?
- February 8 to April 18 (Best seen: February 28 to March 20)
- June 11 to July 31 (Best seen: June 27 to July 16)
- October 9 to November 28 (Best seen: October 18 to November 1)
- January 1 to February 7 (Best seen: January 15 to January 31)
- April 19 to June 10 (Best seen: May 3 to May 24)
- August 1 to October 8 (Best seen: August 31 to September 21)
- November 29 to December 31
Mercury will be brightest and easiest to spot in the evening sky between May 3 and May 24; brightest and easiest to spot in the morning sky between October 18 and November 1.
After the Moon, Venus is the brightest natural object in the night sky. It is both the Earth’s closest neighbor in our Solar System and the planet most similar to Earth in size, gravity, and composition. We can’t see the surface of Venus from Earth, because it is covered with thick clouds. Venus has the densest atmosphere of the four terrestrial planets (Mercury, Venus, Earth, and Mars), which consists mostly of carbon dioxide. Always brilliant, and shining with a steady, silvery light.
When the year opens, it will be visible very low near the east-southeast horizon about 90 minutes before sunrise. Within several weeks it moves too close to the Sun to be seen. Superior conjunction is on March 26. Venus will be out of view until late spring when it emerges above the west-northwest horizon soon after sunset. It will gradually increase in prominence through the balance of the year. Its greatest angular distance (elongation) east of the Sun is on October 29. Venus will attain its greatest brilliancy in the evening sky on December 5. Through December it will resemble a striking crescent phase, getting progressively larger and thinner in telescopes and steadily-held binoculars.
When Is Venus Visible in 2021?
- January 1 to March 25th (Best seen January 1 to 23; in the eastern sky)
- March 26 to December 31 (Best seen May 24 to December 31; in the western sky at dusk)
Mars is the fourth planet from the Sun in our Solar System. While it’s not our nearest neighbor (Venus takes that honor), or the brightest planet in the night sky (also Venus), it is perhaps the planet that most inspires our imagination. Whether as home to “little green men” or as a future outpost for life from Earth, the planet figures heavily into science fiction books and movies. Mars is often called the “Red Planet” because it appears orange-red in the sky, and its surface material contains a lot of iron oxide. Iron looks black, but the element takes on a reddish tinge when it has been exposed to oxygen, i.e., “iron oxide.”
Coming off a spectacular autumn apparition in 2020 when Mars came within 38.6 million miles (62.1 million km) of Earth and briefly became the third brightest object in the night sky, this planet has since fallen behind Earth and is receding, growing smaller and dimmer each night. On New Year’s Day, it resembled the brilliant star Arcturus, both in terms of color and brightness; thus is at its brightest at the very start of the year.
Positioned against the stars of Pisces, Mars is high in the south-southeast at nightfall and will not set until 1:30 a.m. In the weeks and months to come, as Mars pulls farther away from Earth its brightness diminishes. By mid-May it has dropped to rank of second-magnitude and it is setting before midnight. When it finally disappears into the sunset fires in late August, it will have receded to 243 million miles (391 million km) away. It then goes on a “sabbatical” of sorts, through the balance of the summer and well into the fall. It finally reappears late in November, low in the east-southeast sky. By New Year’s Eve, it will be rising around 5:30 a.m., shining at magnitude +1.5 among the stars of the non-zodiacal constellation of Ophiuchus. It will be well on its way toward another bright opposition which will take place almost a year later on December 8, 2022,
When Is Mars Visible in 2021?
- October 8 to December 31(Best seen: November 24 through December 31)
- January 1 to October 7 (Best seen: January 1 through August 22)
Jupiter is usually the third brightest object in the night sky, after the Moon and Venus (only Mars, our next-door neighbor, is occasionally brighter), and summer is an especially good time to view this bright behemoth. Jupiter’s signature feature, the “Great Red Spot,” is actually a colossal storm that has been raging on the planet’s surface since at least the 17th century, when it was first seen by telescope. It’s known as the Gas Giant” because although it looks solid, it is made up primarily of gases, such as hydrogen and helium.
Through all of 2021, the King of the planets will be situated against the star background of Capricornus the Sea Goat. Jupiter will shine like a dazzling, non-twinkling, silvery “star.”
When Is Jupiter Visible in 2021?
- January 29 to August 19 (Best seen: February 17 to August 19)
- January 1 to January 28 (Best seen: January 1 to 9)
- August 20 to December 31 (Best seen: August 20 to December 31)
Brightest in 2021: August 8 to September 2. Jupiter is at opposition to the Sun on August 20.
Saturn is the sixth planet from the Sun, and the second largest, after Jupiter. It is one of the five planets visible from Earth using only the naked-eye (the others are Mercury, Venus, Mars and Jupiter). Though remote from the Earth, Saturn’s unique ring system makes it possibly the most instantly recognized planet in our Solar System. Though about 833 Earths would fit into Saturn, the planet’s density is only one-eighth that of the Earth, making Saturn’s mass barely 95 times greater than the Earth’s.
The famous rings are only visible in a telescope. They were at their maximum tilt toward Earth in October 2017 and are now closing to our line of sight. All through 2021, Saturn will found within the boundaries of Capricornus the Sea Goat.
Saturn is at opposition to the Sun on August 2.
When Is Saturn Visible in 2021?
- January 24 to August 1 (Best seen: February 10 to August 1)
- January 1 to January 23 (Best seen: January 1 to 6)
- August 2 to December 31 (Brightest in 2021: August 1 to August 4.)
Uranus (pronounced “EUR-an-iss) is the 7th planet from the Sun, the smallest of our Solar System’s gas planets, and the first to be discovered by scientists. Uranus is so far away from us, it usually can’t even be seen with the naked eye. the planet is also notable for its dramatic tilt, which causes its axis to point nearly directly at the Sun. It’s sometimes called “The Bull’s Eye Planet,” because of its complex rings and Moons make it appear like a bull’s eye, and the “Ice Giant,” because of its cold atmosphere, and 80% or more of its mass is made up of a mix of water, methane, and ammonia ices.
Uranus can be glimpsed as a naked-eye object by people who are blessed with good eyesight and a clear, dark sky, as well as a forehand knowledge of exactly where to look for it. It shines at magnitude +5.7 and can be readily identified with good binoculars. A small telescope may reveal its tiny, greenish disk. Uranus spends all of 2021 in the constellation of Aries the Ram.
When Is Uranus Visible in 2021?
- April 30 to November 3 (Best viewed: May 16 to November 3)
- January 1 to April 29 (Best viewed: January 1 to April 12)
- November 4 to December 31
Brightest in 2021: August 28 to December 31. Uranus will arrive at opposition to the Sun on November 4.
Neptune is the eighth, and farthest planet in our Solar System and the first whose existence was theorized before its actual discovery. Like Jupiter, Saturn, and Uranus, Neptune is called a “gas giant” because, though it looks solid, it is made up primarily of gases, such as hydrogen and helium, covering a rocky core comprised of heavier elements. Neptune has 13 moons and takes 165 years to take 1 trip around the Sun!
It’s sometimes called “The Blue Planet,” because Neptune’s cloud cover has an especially vivid blue tint. Astronomers aren’t quite sure what compound causes the blue tint and theorize it may the result of the absorption of red light by methane in the planets mostly hydrogen-helium atmosphere.
Neptune spends all of 2021 in the constellation of Aquarius the Water Carrier. At a peak magnitude of +7.8, this bluish-hued world is only visible with good binoculars or a telescope.
When Is Neptune Visible in 2021?
- March 27 through September 13
- January 1 through February 23
- September 14 to December 31
Brightest in 2021: July 19 to November 8. Opposition is on September 14.
Please note all the images of the planets depicted in this story are stock photography/artist’s renderings and not actual photographs.