Jupiter and Saturn stay quite close in the May predawn or dawn sky, but are gradually migrating away. Both planets are far up before the first light of dawn and will be easier to see in the early morning hours than they were last month. The two planets are helping to mark the beginning of summer in the Northern Hemisphere.
Jupiter is rising about an hour after midnight and will be high in the southeast around 4:00 a.m. Saturn is rising about an hour before midnight and will be high in the west around 3:30 a.m.
These are bright objects for the eye to observe even without a telescope. They can be seen with the naked eye as a golden-yellow "star" with a blue-white hue.
Jupiter is the largest planet in the solar system and contains more than 10% of the mass of all the other planets combined. It plays a major role in determining the course of events on Earth, so it's not surprising that people have been watching its movements for many years with telescopes. As well as being able to see Jupiter with the unaided eye, astronomers have estimated its diameter from 1.5 miles (2.4 km) to 6.4 miles (10 km).
Saturn is the second-largest planet and the most distant of the eight planets from our sun.
A conjunction of the two planets occurs around every 20 years. However, the last time Jupiter and Saturn were so near in the sky as they were on Monday was in 1623, during a daytime alignment that was not visible from most areas on Earth. The next conjuction is not until 2426.
Conjunctions between Jupiter and Saturn are important events in astronomy. They can have a profound effect on the environment here on Earth, on animals, and on people. Conjunctions affect weather by altering the paths that planets take through space; sometimes they cause cold snaps or heat waves, depending on which planet is responsible for the change. They can also have an impact on people through natural disasters like earthquakes and floods. Last but not least, conjunctions influence the appearance of the night sky, because both planets are very bright objects when seen from Earth.
Jupiter and Saturn are always visible to the naked eye, but on Monday they appeared quite close together in the east just after midnight. Astronomers use the word "conjunction" to describe when two celestial bodies are closer than the distance between them, which is about 5 degrees for Jupiter and Saturn. Because they're so far away from us, only telescopes can reveal details about their surfaces that are invisible to the human eye.
Astronomers use telescopes on Earth and on other planets to learn more about our solar system and other stars beyond ours.
Look for Jupiter and Saturn low in the southwest in the hour after sunset to see their approach and final conjunction, according to NASA. They will be activated prior to 8 p.m. local time.
Jupiter and Saturn are the two most massive planets in the Solar System. When they are close together like this from Earth they are called "conjunctional". At this time, they are also on opposite sides of our Sun so they can't be seen from here as stars. Instead, you have to look at them across Earth's atmosphere where they will appear as a faint glow in the sky.
In addition to being visible in daylight skies, Jupiter and Saturn are always bright enough to see with the naked eye from anywhere on Earth during the month of June. They reach their highest points in the sky just before midnight, when they are located in the west after sunset.
Saturn is about 508 million miles from Earth while Jupiter is 595 million miles away. They are both large enough to be visible with the naked eye, but only from certain locations. If you live somewhere else, you'll have to wait until sometime in the future to see them again.
People have been watching Jupiter and Saturn for centuries without even knowing it. Scientists use this phenomenon to find out how far away other planets are.
Though Jupiter and Saturn look to be 456 million miles (734 million km) apart on the sky's dome right now, they are truly 456 million miles (734 million km) apart. Saturn is roughly twice as far away from Jupiter as Jupiter is from Saturn.
Jupiter is about 93 million miles (150 million km) from the Sun, while Saturn is about 94 million miles (153 million km) from the Sun. So, you could say that Jupiter is close compared to Saturn because it takes 11 years for Jupiter to make one orbit around the Sun, while it takes 29 years for Saturn to make one orbit. This is why Jupiter is called the King of Planets and Saturn the Lord of Rings.
Now, here's where things get tricky. Don't forget that Jupiter and Saturn move at different speeds in their orbits around the Sun. As Jupiter travels farther from the Sun, it becomes hotter than Saturn. Also, since Jupiter has more mass, it pulls on Saturn, causing it to rotate faster than Saturn would otherwise rotate. In other words, Jupiter and Saturn behave like a pair of gears - one large, one small. The closer together they lie, the harder they turn; the further apart, the slower they turn. This is why astronomers call this configuration a "gas giant."
Earth also is a gas giant, but it isn't very big.
Jupiter will be at opposition on August 19, meaning it will be visible whenever the sky is dark, peaking about midnight. It currently burns directly on the Capricorn-Aquarius equinox, and appears early in the evening twilight, but it's still somewhat low in the southeast.
Jupiter is the largest planet in our solar system and by far the most massive object beyond Earth's atmosphere. It has been known as a godhead and a power greater than ourselves because of its influence on other planets and objects in the solar system. Scientists believe that it caused other planets to form from dust clouds around the Sun.
In Greek mythology, Zeus married Hera in order to formed a child with her, therefore getting two mothers. In similar fashion, scientists believe that Jupiter formed around another star and then migrated toward the Sun when they became close friends. The more massive Jupiter attracted even more material from the surrounding space and grew larger over time.
The word "planet" comes from the name given to the moons of Jupiter and Saturn by ancient Greeks: Io, Europa, Ganymede, and Callisto. These bodies were not considered stars because they did not shine light of their own. Instead, they reflected the sun's light like a mirror. Today we know them as the four largest satellites of Jupiter and Saturn, respectively.
On the dome of the sky, Saturn is close to the east of Jupiter. The two are noteworthy due to their brightness and proximity to one another. Photos from the EarthSky Community Observatory show them both as stars - with bright lights like those from cities on Earth - but they're actually planets that orbit a common center of gravity called the Sun.
Saturn is approximately 930,000 miles away from Earth while Jupiter is about 494 million miles away. They appear close together because Jupiter is about half the size of Saturn.
Also visible in the night sky are Venus, Moon and some stars such as Alpha Centauri. All will be below the horizon during dawn today, so look after an hour or two past midnight for best viewing prospects.
Venus will be rising soon after midnight this morning, just before the Sun does. It's easy to spot against the brighter-than-average sunrise sky glow, with Mars further to its west and Uranus farther to its north.
The Moon is also easy to find, lying almost directly across the middle of the sky from Venus to the southwest toward Alpha Centauri. It's hard to miss.
As soon as it's light enough, head outside and look up. You should see Saturn, right next to Jupiter.