January 2025
The Sky Tonight - January 2025
January continues the season of Birak, and the hot weather isn’t going anywhere anytime soon. The night sky presents a parade …
ExploreFull Moon
April 6
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The casual observer
The Ningaloo Total Solar Eclipse occurs on April 20. The path of totality of this eclipse grazes the northwest coast of Western Australia and is going to be quite a spectacle.
Image: Path of totality of the Ningaloo eclipse.
Credit: timeanddate
Perth will experience a partial solar eclipse, with approximately 70% of the Sun being covered by the Moon. It won’t be completely dark, but you will definitely notice the shadows.
Image: The peak of the eclipse as observed from Exmouth (L) and Perth (R).
Credit: timeanddate
Eclipses are as beautiful as they are fleeting and are caused by a cosmic accident. By coincidence, the Sun is 400 times the diameter of the Moon and is also 400 times further away. These two factors combine to make the Sun and the Moon appear roughly the same size in our sky, allowing total solar eclipses to happen. Location, time and coincidence all combine to create something beautiful.
There’s more about the total solar eclipse further down this page, and there is a dedicated section of the Scitech website if you want even more.
April brings us into the season of Djeran, which usually means things would cool down a bit over the next couple of months. However, if the Bureau of Meteorology climate forecasting is accurate, we might be in for a little warmer weather and some clearer nights still.
Image: Not cloudy with a chance of higher than median temperatures
Credit: Bureau of Meteorology
Venus is hanging low on the western horizon during the early evenings all month. It will continue to get brighter as the days go on.
ISS sightings from Perth
The International Space Station passes overhead multiple times a day. Most of these passes are too faint to see but a couple of notable sightings are:
| Date, time | Appears | Max Height | Disappears | Magnitude | Duration |
| 10 Apr 05:34 AM | 17° above SW | 85° | 10° above NE | -3.8 | 6 min |
| 16 Apr 6:54 PM | 10° above NW | 83° | 20° above SE | -3.8 | 5.5 min |
Table: Times and dates to spot the ISS from Perth
Source: Heavens above, Spot the Station
Dates of interest
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The International Mathematical Union will promote the number 8 to the status of largest even prime.
April 1
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NASA will announce the members of Artemis 2, the first crewed mission to the Moon since 1972.
April 3
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Ningaloo Total Solar Eclipse
April 20
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Moon close to Venus
April 23
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Moon close to mars
April 26
Planets to look for
Mercury and Venus are visible in the west after sunset. Mercury is very low and faint and only visible for the first couple of weeks of the month.
By contrast, Venus just seems to hang there. Because of the relative positions of Venus and Earth on their orbits, Venus will be visible in the western sky during the evenings for the next few months. If you are out in the evening looking at something bright in the western sky, it’s almost certainly Venus. We get quite a few queries here at the Scitech Planetarium asking about the bright object visible in the west.
Which reminds me, I have to go set my automated emails, be right back.
Image: That’s better
Mars is also there in the northwest and spends the month moving through Gemini. This makes it a useful anchor to help spot this otherwise (with the exception of Castor and Pollux) faint constellation.
Image: Review: This constellation is underwhelming. I give it two stars!
Constellation of the month
Leo the Lion
Leo is a large constellation visible in the northern skies during the middle months of the year. Unlike most constellations, the prominent star patterns in Leo actually look like the artistic interpretation, with the distinctive pattern of stars making up the mane standing out prominently.
Image: The stars making the mane have their own nickname – the sickle.
Viewing it from the southern hemisphere, it is easier to think of it as an upside down question mark and a companion triangle.
In mythology, Leo is taken to be the Nemean Lion slain by Heracles (Hercules) in the first of his twelve labours. The lion was said to have golden fur that could not be damaged by mortal weapons, so Heracles strangled it to death with his bare hands instead.
The brightest star in Leo is Regulus, the front foot of the lion or the base of the question mark, and upon closer inspection is revealed to be a quadruple star system consisting of a pair of binary stars.
Leo is also home to the Dwarf Galaxies Leo I and Leo II. Located only 12 arc minutes from Regulus, Leo 1 is about 800 000 light years away and possibly a very distant satellite of the Milky Way, while Leo II is a confirmed satellite around 700 000 light years away. Satellite galaxies are thought to be the remnants of once larger galaxies that have been consumed by the milky way in acts of galactic cannibalism.
Image: Regulus (top) and the Leo I Dwarf
Credit: Chris Cook, APOD.
Object for the small telescope
Venus and its phases
Since it will be visible on the western horizon until about August, now is a good time to start a little project to track the phases of Venus. Venus is in the process of overtaking Earth as the two planets orbit the Sun. This means we will see Venus at ever sharper angles as the weeks go on, seeing less and less of its sunlit face. Thus, we can expect to see the crescent of Venus’s day side get narrower over the coming months. Now is the time to start.
Image: Simulation of phase and relative size of Venus from April – July 2023
Observing Venus is made complicated by the fact that it will be low on the horizon after sunset but is aided by the fact that the combination of the planets size, proximity and reflectivity make it impressively bright.
Conveniently, by the time Venus leaves the evening skies in late July, it will be right next to Regulus in the sky.
Feature Article
The Ningaloo Total Solar Eclipse – A Scitech Perspective
Scitech has been preparing for the Ningaloo Total Solar Eclipse for some time so we can share information, facts and provide context around why this is such a significant astronomical event.
Even if you don’t often take an interest in space or the night sky, the mystery and rarity of eclipses can often lead to more curiosity and questions … and that’s where Scitech can help.
We are excited to collaborate and co-host a livestream broadcast with the Singapore Science Centre. This will be available for viewing across the Asia Pacific Network of Science and Technology Centres, a network of dozens of science museums similar to Scitech. This broadcast will offer experts, commentary and interviews, including one from myself, across the three hours of the eclipse, providing front row seats to the whole experience, and the opportunity to inspire and engage audiences beyond Western Australia.
The livestream will be available online, and be shown in the Scitech Discovery Centre on Thursday, 20 April.
Heading north will be three teams of Scitech personnel travelling during the week of the event.
Two teams will travel to Exmouth by road, including a stop at the Carnarvon Space and Technology Muesum to deliver a special presentation. Once in Exmouth, Scitech will support the Shire of Exmouth’s eclipse event as part of the Dark Sky Festival, which will feature Scitech’s interactive exhibits and live presentations.
Our third team will be flying into Exmouth and be based at the official Ningaloo viewing area. It turns out Scitech’s CEO is an amateur astronomer who has filmed eclipses in the past and will be leading this team while they communicate with visitors and the media.
Other space news
Scientists reveal a geological model of Earth over the last 100 million years.
ASKAP observations shed light on a 2 billion year old Gamma Ray Burst.
The James Webb Space Telescope finds no evidence for any atmosphere on Trappist 1b.
