When and How to Spot the ‘Devil Comet’

Comet 12P/Pons-Brooks is one of the brightest known periodic comets. It earned the nickname of “devil comet” in 2023 when an outburst caused the comet to have an asymmetrical appearance, like having horns. It comes around every 71 years and is currently getting brighter as it flies toward the Sun.

As spring approaches for northern skygazers, Comet 12P/Pons-Brooks is growing brighter. Currently visible with small telescopes and binoculars, the Halley-type comet could reach naked eye visibility in the coming weeks. Seen despite a foggy atmosphere, the comet's green coma and long tail hover near the horizon in this well-composed deep night skyscape from Revuca, Slovakia recorded on March 5. M31, also known as the Andromeda galaxy, and bright yellowish star Mirach, second brightest star in the constellation Andromeda, hang in the sky above the comet. The Andromeda galaxy is some 2.5 million light-years beyond the Milky Way.
As spring approaches for northern skygazers, Comet 12P/Pons-Brooks is growing brighter. Currently visible with small telescopes and binoculars, the Halley-type comet could reach naked eye visibility in the coming weeks. Seen despite a foggy atmosphere, the comet’s green coma and long tail hover near the horizon in this well-composed deep night skyscape from Revuca, Slovakia recorded on March 5. M31, also known as the Andromeda galaxy, and bright yellowish star Mirach, second brightest star in the constellation Andromeda, hang in the sky above the comet. The Andromeda galaxy is some 2.5 million light-years beyond the Milky Way.
Image Credit & Copyright: Petr Horálek / Institute of Physics in Opava

In the Northern Hemisphere, the comet is best viewed with binoculars or a small telescope – right after the Sun dips below the horizon, look West just beneath the Moon, and just right of Jupiter. An hour after sunset, the comet drops so low, it will be difficult to see without a perfectly clear view of the horizon. The comet then sets an hour later.

Sky chart showing the crescent Moon above Jupiter and Comet 12P in the western sky following sunset on April 10.
Sky chart showing the crescent Moon above Jupiter and Comet 12P in the western sky following sunset on April 10.
Credit: NASA/JPL-Caltech

Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, encourages viewers to have more realistic expectations about what they might see. “Many images depict a bright comet with a long green tail,” Cooke said. “That’s not going to happen.”

By July, it will be too dim to view even with binoculars.

As for viewing this comet with the naked eye, it might be possible in the coming days, but by mid-April, it will be too close to the Sun and then growing fainter as it makes its way away from the Sun.

The brightest stars are a magnitude 1, the faintest are a magnitude 6. Comet 12P will peak around a magnitude 5 unless an outburst occurs.

However, Cooke warns that outbursts are unpredictable. “There have been minor outbursts roughly once a month but it’s impossible to predict them,” he said. “The last one was on Leap Day, Feb. 29.”

Will the comet be visible during the eclipse?

It is certainly a possibility. If Comet 12P remains around a magnitude 5, it would only be visible in binoculars during the few minutes of totality. Consider enjoying the main spectacle instead of using that time to locate Comet 12P and attempt to view it at another time.

For more skywatching highlights in April, check out Jet Propulsion Lab’s What’s Up series.

By Lauren Perkins
NASA’s Marshall Space Flight Center

It’s All About Mars in October

by Lance D. Davis

NASA is developing a path for an exciting journey to Mars – a rich destination for scientific discovery and human exploration as we expand our presence into the solar system. This month of October brings an amazing night-sky view of the Red Planet.

Mars is currently visible, reaching its highest point in the sky around midnight. Earth’s closest neighbor is also at its brightest and will remain that way well into November.

Two illustrations contrasting Mars’ position when it reaches opposition and conjunction. During opposition, like in October 2020, Earth passes near Mars – which is easily visible and bright. During conjunction, Mars and Earth are far from each other, so Mars appears small and faint.
Two illustrations contrasting Mars’ position when it reaches opposition and conjunction. During opposition, like in October 2020, Earth passes near Mars – which is easily visible and bright. During conjunction, Mars and Earth are far from each other, so Mars appears small and faint. Credit: NASA

Right now, Mars is the third brightest object in Earth’s night. The Moon and Venus are the two brightest objects, and usually Jupiter is third. But for this season, Mars is passing close enough to Earth to outshine Jupiter. This great visibility of Mars coincides with an event known as opposition, which happens every two years and two months.

Opposition occurs when the orbit of a planet, such as Mars, takes it near the Earth. Just like runners passing each other on a track, the faster, inner planets, such as Earth, can approach and overtake slower-moving outer planets like Mars. When the planets pass each other during this opposition, Mars’ proximity means it will appear larger and brighter in our sky. Because the Sun, Earth, and Mars are lined up during this passing, Mars will rise at sunset, having a high overhead at midnight. This is the closest the Red Planet will come to Earth for the next 15 years, or until September 2035.

At its furthest, Mars reaches about 250 million miles (400 million km) from Earth. During the October opposition, it will be as close as 40 million miles (60 million km) – nearly seven times closer. Although Mars will still look like a bright star to the unaided eye, it will grow dramatically in size when seen in a telescope. This year, Mars’ closest approach to Earth happens just a week before the opposition on Oct. 13, giving the Red Planet its biggest, apparent size of the 2020’s.

When it comes to observing Mars around opposition, telescopes will show more of the planet’s details, such as dark and light regions on Mars’ surface, and the prominent south polar ice cap, which will be tilted towards the Earth. Due to the turbulence of our atmosphere, these details can be hard to see, especially in smaller telescopes.

Many amateur astronomers use a color video camera attached to their telescope, running special software that selects the best frames to stack into a single image. This helps in negating the blurring caused by the air.

The most striking thing about Mars’ appearance – whether seen with the naked eye or through a telescope – is its red color. This color is caused by iron in the rocks on Mars’ surface – the same thing that causes the red color in sandstone formations in the southwestern US.

So, when you spot Mars, keep your eye on it and enjoy its fiery, red brightness!