Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
5 Min Read Planetary Alignments and Planet Parades
A sky chart showing Mars, Jupiter, Saturn, and Venus in a “planet parade.” Credits:
NASA/JPL-Caltech On most nights, weather permitting, you can spot at least one bright planet in the night sky. While two or three planets are commonly visible in the hours around sunset, occasionally four or five bright planets can be seen simultaneously with the naked eye. These events, often called “planet parades” or “planetary alignments,” can generate significant public interest. Though not exceedingly rare, they’re worth observing since they don’t happen every year.
Why Planets Appear Along a Line in The Sky
“Planet parade” isn’t a technical term in astronomy, and “planetary alignment” can refer to several different phenomena. As the planets of our solar system orbit the Sun, they occasionally line up in space in events called oppositions and conjunctions. A planetary alignment can also refer to apparent lineups in our sky with other planets, the Moon, or bright stars.
The planets of our solar system always appear along a line on the sky. This line, referred to as the ecliptic, represents the plane in which the planets orbit, seen from our position within the plane itself. NASA/Preston Dyches When it comes to this second type of planetary alignment, it’s important to understand that planets always appear along a line or arc across the sky. This occurs because the planets orbit our Sun in a relatively flat, disc-shaped plane. From Earth, we’re looking into that solar system plane from within. We see the racetrack of the planets from the perspective of one of the racers ourselves. When viewed edge-on, this disc appears as a line, which we call the ecliptic or ecliptic plane.
So, while planet alignment itself isn’t unusual, what makes these events special is the opportunity to observe multiple planets simultaneously with the naked eye.
Will the Planets Actually be Visible?
Before preparing to observe a planet parade, we have to consider how high the planets will appear above the horizon. For most observers to see a planet with the naked eye, it needs to be at least a few degrees above the horizon, and10 degrees or higher is best. This is crucial because Earth’s atmosphere near the ground dims celestial objects as they rise or set. Even bright planets become difficult or impossible to spot when they’re too low, as their light gets scattered and absorbed on its path to your eye. Buildings, trees, and other obstructions often block the view near the horizon as well.
This visibility challenge is particularly notable after sunset or before sunrise, where the sky is still glowing. If a planet appears very low within the sunset glow, it is very difficult to observe.
The Planets You Can See, and Those You Can’t
Five planets are visible without optical aid: Mercury, Venus, Mars, Jupiter, and Saturn. Ancient civilizations recognized these worlds as bright lights that wandered across the starscape, while the background stars remained fixed in place. In fact, the word “planet” comes to us from the Greek word for “wanderer.”
The solar system includes two additional major planets, Uranus and Neptune, plus numerous dwarf planets like Pluto and Ceres. Uranus and Neptune orbit in the dim, cold depths of the outer solar system. Neptune absolutely requires a telescope to observe. While Uranus is technically bright enough to detect with good eyesight, it’s quite faint and requires dark skies and precise knowledge of its location among similarly faint stars, so a telescope is recommended. As we’ll discuss in the next section, planet parades necessarily must be observed in twilight before dawn or after sunset, and this is not a good time to try observing extremely faint objects like Uranus and Neptune.
Thus, claims about rare six- or seven-planet alignments which include Uranus and Neptune should be viewed with the understanding that these two distant planets will not be visible to the unaided eye.
What Makes Multi-Planet Lineups Special
Lineups of four or five planet naked-eye planets with optimal visibility typically occur every few years. Mars, Jupiter, and Saturn are frequently seen in the night sky, but the addition of Venus and Mercury make four- and five-planet lineups particularly noteworthy. Both orbit closer to the Sun than Earth, with smaller, faster orbits than the other planets. Venus is visible for only a couple of months at a time when it reaches its greatest separation from the Sun (called elongation), appearing just after sunset or before sunrise. Mercury, completing its orbit in just 88 days, is visible for only a couple of weeks (or even a few days) at a time just after sunset or just before sunrise.
Planet parades aren’t single-day events, as the planets move too slowly for that. Generally, multi-planet viewing opportunities last for weeks to a month or more. Even five-planet events last for several days as Mercury briefly emerges from and returns to the Sun’s glare.
In summary, while they aren’t once-in-a-lifetime events, planetary parades afford an uncommon opportunity to look up and appreciate our place in our solar system, with diverse worlds arrayed across the sky before our very eyes.
Other Planet Lineups
Other recent and near-future multi-planet viewing opportunities:
January 2016 – Four planets visible at once before sunrise Late April to Late August 2022 – Four planets visible at once before sunrise Mid-June to Early July 2022 – Five planets visible at once before sunrise January to mid-February 2025 – Four planets visible at once after sunset Late August 2025 – Four planets visible at once before sunrise Late October 2028 – Five planets visible at once before sunrise Late February 2034 – Five planets visible at once after sunset (Venus and Mercury challenging to observe) About the January/February 2025 Planet Parade
The current four-planet lineup concludes by mid-February, as Saturn sinks increasingly lower in the sky each night after sunset. By mid-to-late February, Saturn appears less than 10 degrees above the horizon as sunset fades, making it difficult to observe for most people. While Mercury briefly joins Saturn in the post-sunset glow at the end of February, both planets will be too low and faint for most observers to spot.
Keep Exploring Discover More Topics From NASA
Skywatching
Planets
Solar System Exploration
Moons
View the full article
-
By NASA
NASA’s SPHEREx space observatory was photographed at BAE Systems in Boulder, Colorado, in November 2024 after completing environmental testing. The spacecraft’s three concentric cones help direct heat and light away from the telescope and other components, keeping them cool. Credit: BAE Systems NASA will host a news conference at 12 p.m. EST Friday, Jan. 31, to discuss a new telescope that will improve our understanding of how the universe evolved and search for key ingredients for life in our galaxy.
Agency experts will preview NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) mission, which will help scientists better understand the structure of the universe, how galaxies form and evolve, and the origins and abundance of water. Launch is targeted for no earlier than Thursday, Feb. 27.
The news conference will be hosted at the agency’s Jet Propulsion Laboratory in Southern California. Watch live on NASA+, as well as JPL’s X and YouTube channels. Learn how to watch NASA content through a variety of platforms, including social media.
Laurie Leshin, director, NASA JPL, will provide opening remarks. Additional briefing participants include:
Shawn Domagal-Goldman, acting director, Astrophysics Division, NASA Headquarters James Fanson, project manager, SPHEREx, NASA JPL Beth Fabinsky, deputy project manager, SPHEREx, NASA JPL Jamie Bock, principal investigator, SPHEREx, Caltech Cesar Marin, SPHEREx integration engineer, Launch Services Program, NASA’s Kennedy Space Center in Florida To ask questions by phone, members of the media must RSVP no later than two hours before the start of the event to: rexana.v.vizza@jpl.nasa.gov. NASA’s media accreditation policy is available online. Questions also can be asked on social media during the briefing using #AskNASA.
The SPHEREx observatory will survey the entire celestial sky in near-infrared light to help answer cosmic questions involving the birth of the universe, and the subsequent development of galaxies. It also will search for ices of water and organic molecules — essentials for life as we know it — in regions where stars are born from gas and dust, as well as disks around stars where new planets could be forming. Astronomers will use the mission to gather data on more than 450 million galaxies, as well as more than 100 million stars in our own Milky Way galaxy.
The space observatory will share its ride on a SpaceX Falcon 9 rocket with NASA’s PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission, which will lift off from Launch Complex 4E at Vandenberg Space Force Base in Central California.
The SPHEREx mission is managed by NASA JPL for the agency’s Astrophysics Division within the Science Mission Directorate at NASA Headquarters in Washington. The principal investigator is based at Caltech in Pasadena, California, which manages NASA JPL for the agency.
The spacecraft is supplied by BAE Systems. The Korea Astronomy and Space Science Institute contributed the non-flight cryogenic test chamber. Mission data will be publicly available through IPAC at Caltech.
For more information about the mission, visit:
https://nasa.gov/spherex
-end-
Alise Fisher
Headquarters, Washington
202-358-2546
alise.m.fisher@nasa.gov
Val Gratias / Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-6215 / 626-808-2469
valerie.m.gratias@jpl.nasa.gov / calla.e.cofield@jpl.nasa.gov
Share
Details
Last Updated Jan 27, 2025 EditorJessica TaveauLocationNASA Headquarters Related Terms
SPHEREx (Spectro-Photometer for the History of the Universe and Ices Explorer) Astrophysics Division Jet Propulsion Laboratory Polarimeter to Unify the Corona and Heliosphere (PUNCH) Science Mission Directorate View the full article
-
By USH
The American Meteor Society website shared a video on their channel showing a fireball streaking across the skies of Michigan and Ohio on Sunday, January 19, 2025, around 01:31 UT.
Though, Meteor Society noted that the video might not actually depict a fireball event, leaving some viewers curious about the meaning behind this statement.
At the moment the fireball appears on camera, a strange object seems to materialize above it, expanding in size and partially obscuring the fireball before gradually fading out as the fireball continues its path through the sky.
This phenomenon has sparked varied interpretations. Some suggest it might indicate alien intervention, while others offer a more plausible explanation: the "object" is likely a water droplet on the camera lens, creating the illusion of interaction with the fireball.
However, since the Meteor Society suggested that it might not actually depict a fireball event, we might question whether it was truly a fireball, a meteor, including a water droplet, or something entirely different.
View the full article
-
By Amazing Space
Winter Sky Guide: Orion, Pleiades & Jupiter Alignment | Meteor Shower Captured! Stargazing
-
By NASA
Peering through the window of the SpaceX Dragon Endeavour spacecraft, NASA astronaut Matthew Dominick captured this image on Oct. 7, 2024 of the SpaceX Dragon Freedom spacecraft as vivid green and pink aurora swirled through Earth’s atmosphere while the International Space Station soared 273 miles above the Indian Ocean.
Visit Dominick’s photography on station to experience the wonders of space through his eyes, enriched by his remarkable journey of orbiting the Earth 3,760 times.
To see a short-term forecast of the location and intensity of the next aurora check this link: Aurora – 30 Minute Forecast and also NASA’s Guide to Finding and Photographing Auroras.
Image Credit: NASA/Matthew Dominick
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.