A supermoon rises over Auckland's Sky Tower in 2021. Astronomers are expecting a pair of supermoons in November and December 2025. Photo / Michael Craig
From eclipses to supermoons and meteor showers, there’ll be plenty of action in New Zealand’s night skies to keep stargazers busy this year. Jamie Morton looks at the highlights.
If Mars appears a little bigger than usual right now, your eyes aren’t deceiving you.
The red planet will be at opposition on Thursday – meaning it’ll be at its closest point to Earth in its orbit.
“Another way to think about is that there is a straight line from the sun to Earth to Mars,” Stardome astronomer Rob Davison said.
“As it is at its closest point to Earth, Mars will appear at its biggest and brightest, meaning around this date is the best time to observe it.”
To the naked eye, it will appear as a relatively bright, star-like point of light near the constellation Gemini – but it will still be dimmer than Venus and Jupiter.
Through a telescope, an observer might be lucky enough to see some surface features, including its polar ice caps, Davison said.
“But as always, specific atmospheric conditions for a given time and location will have a major bearing on how clear any views may prove to be.”
Globally, lunar and solar eclipses aren’t particularly rare: they’re visible somewhere on Earth several times a year.
But getting a few chances to see these spectacles from the same place – as Kiwis will get to in 2025 – is a different story.
Davison said a given location on Earth typically gets around two or three lunar eclipses – full or partial – within a roughly two-year period, before not seeing another for a similar period of time.
These happen when Earth is positioned directly between the sun and the moon, casting a shadow on the moon’s surface.
“Because Earth is much larger than the moon, it is possible for Earth’s shadow to be cast over the entire face of the moon: a total lunar eclipse.”
Kiwis will be able to see a total lunar eclipse twice this year.
The first, on March 14, will be occurring as the moon is rising early in the evening, while the second, on September 8, will happen as the moon is setting early in the morning.
People wanting to see the lunar eclipses won’t need any special equipment, Davison said: just a clear line of sight to the respective horizon.
Solar eclipses – which certain places can wait decades or even centuries to see – come about in essentially the opposite way to lunar ones.
The moon is positioned directly between the sun and Earth, blocking the sun’s light and casting a shadow on Earth’s surface.
“Only a small amount of Earth’s surface can be fully cast in shadow by the moon at any given time, which leads to a ‘path of totality’ as this area of full shadow moves across the surface,” Davison said.
Areas outside the path of totality may experience a partial solar eclipse, he added – and not all solar eclipses were total.
On the morning of September 22, there’d be a partial solar eclipse – with around 60% to 70% coverage – and New Zealand happens to be one of the best spots in the world to observe it.
“Anyone wanting to view the partial solar eclipse must make sure they take all appropriate precautions and not stare directly at the sun – we cannot stress this enough.”
We’ve all heard much about supermoons, be they “blue supermoons” or “super blood wolf moons”.
Davison notes while “supermoon” isn’t a formal astronomical term, it can be useful as a way to tell people which full moons appear largest in any given year.
“The moon’s distance from Earth varies slightly as it travels in its orbit around us,” he explained.
When a full moon coincides with the point of closest approach, it appears slightly bigger and brighter than average.
This was what’s known as a supermoon; the opposite is sometimes called a micromoon.
“Depending on how strictly we define it, there are at least two and up to four supermoons every single year, and they always happen consecutively.”
This year, there’s two supermoons on the calendar, but they’re some way away: on November 6 and December 5.
Another annual treat for stargazers are meteor showers, which play out in our night skies when Earth passes through an area of space containing natural debris.
These small pieces of debris then burn up in Earth’s atmosphere, creating small streaks or flashes of light known as meteors or shooting stars.
“Most commonly, these pieces of debris are left over from comets that have passed through the inner solar system sometime in the past,” Davis said.
One of the most famous, Halley’s Comet, is responsible for the Eta Aquariids showers, as well as the Orionids shower each October.
Davison said the Eta and Delta Aquariids showers, usually the best viewed from here in the Southern Hemisphere, should produce rates of 30 meteors per hour.
“The moon can be a big factor in determining how visible meteors might appear during the shower – with a full moon being bad news – but fortunately it shouldn’t be too much of an issue for any of the three in 2025.”
The Eta Aquariids shower can be observed on May 7, the Delta Aquariids on July 30, while the Geminid shower, likely to produce similar rates, is expected on December 14.
For space enthusiasts, this was the year in which humans were going to make their first trip to the moon since Nasa’s Apollo 17 mission, 52 years ago.
Nasa’s Artemis II mission – set to take four astronauts on a trip to the moon and back – has been pushed back to at least April next year, but there’ll be plenty of other events to follow.
One is BepiColombo, a joint mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (Jaxa) to Mercury.
The spacecraft isn’t due to start orbiting Mercury until 2026, but a fly-by of the planet this month is part of a long journey to reach that point.
Similarly, ESA’s Juice spacecraft, designed to explore the icy moons of Jupiter, is set to make a fly-by of Venus in August, while Nasa’s probe Lucy will whiz by Donaldjohanson – one of eight different asteroids it’s observing on a 12-year journey – in April.
Ahead of the next Artemis missions, Davison said there’s also plenty of focus on the moon.
IM-2 and IM-3 missions will deliver multiple Nasa payloads there in January and October.
In the commercial space, Blue Origin is slated to launch its Blue Moon lunar lander in March, and Astrobiotic its own Griffin lunar lander in September.
Firefly’s Blue Ghost lunar lander will launch from Florida in mid-January on a SpaceX Falcon 9, carrying 10 Nasa payloads for a 60-day mission to the moon’s Mare Crisium basin.
Sharing the ride is Japanese firm ispace’s Hakuto-R Mission 2 lander, which will take a low-energy path to the Mare Frigoris region, aiming to land four to five months later.
Davison said the potential end of the Juno spacecraft’s mission in September will prove another big milestone.
“It has been in orbit for almost a decade and has sent back some truly astounding observations of Jupiter and its moons,” he said.
“The original plan was to deliberately have it plunge into Jupiter’s atmosphere, though this may be extended if Nasa believes it can still fulfil a useful purpose.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
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