What's Happening in Space: April 2026

A summary of space events through the month

This April, resident Space Expert, Dhara Patel, joins us once again to share star gazing opportunities and the latest space happenings!

Throughout April - Spot the International Space Station

From Leicester, there may be sightings throughout April to spot the International Space Station (ISS) moving across the sky. Download NASA’s Spot the Station app using the App Store or Google Play to find out when and where to spot the largest artificial satellite overhead from your location. It’ll look like a bright star moving relatively quickly across the sky (generally from west to east) and will be visible to the naked eye.

Throughout April – Stargazing challenges

Each month, we'll be sharing some stargazing challenges for everyone to have a go at. From spotting the Moon and familiar star patterns, to catching meteor showers and eclipses. Check out our Stargazing Challenges – April 2026 blog for more details.

1st April - Artemis II Launch

Following a successful outcome after the second wet dress rehearsal of the Space Launch System rocket and Orion capsule (where technicians load the vehicle with fuel before running through a countdown to launch to check everything is working ahead of launch day), engineers discovered an issue with the flow of helium to the rocket’s upper stage. It required the SLS and Orion to be rolled back into the Vehicle Assembly Building to investigate the cause of the issue and fix it pushing the launch of Artemis 2 back to April. The Rocket and spacecraft are now back on the launchpad readying for a launch attempt on 1^st April at 23:24 (UK-time). If the launch is postponed there are further launch opportunities on 3^rd – 7^th April (UK-time) and another window which would begin on 30^th April.

We’re planning on delivering a mission update at the National Space Centre following the launch: https://www.spacecentre.co.uk/whats-on/artemis-ii-mission-update-day/

Artemis 2 will be the first crewed flight in the Artemis Program. Launching on the SLS (Space Launch System) rocket, the Orion module spacecraft will carry NASA Astronauts commander Reid Wiseman, pilot Victor Glover, mission specialist Christina Koch and Canadian Space Agency astronaut Jeremy Hansen, making a 10-day journey around the Moon and back to Earth. Though they won’t be landing on the Moon, the astronauts will be helping to test many of the onboard systems including communication, life support, and navigation.

NASA have also announced an update to the architecture of the Artemis Program adding an extra mission into the timeline. The Artemis III mission, now in 2027, will be designed to test out systems and operational capabilities in low Earth orbit to prepare for an Artemis IV crewed landing in 2028. Artemis III aims to include a rendezvous and docking with one or both commercial landers from SpaceX and Blue Origin – the spacecrafts that will take humans from lunar orbit to landing on the Moon in Artemis IV. Artemis III will also test the new Extravehicular Activity (xEVA) suits ahead of them being used on the first lunar landing mission. You can find out more in our blog Artemis: Returning Humans to the Moon blog written by Ed Kellond-Turner in our Education team.

3rd April - Mercury at greatest western elongation

Because Mercury orbits closer to the Sun than Earth, it always appears quite close to the Sun in the sky, being lost in its glare most of the time. However, Mercury will be at its furthest separation from the Sun as seen from Earth on 3rd April when it reaches greatest western elongation, making it a great time to try and spot the Sun’s closest planet. Look to the east just before sunrise – it will look like a star-like point visible to the naked eye but will be incredibly close to the horizon, so you’ll need a good clear view without tall buildings and trees. Find out more about greatest elongations in our Astronomical phenomena blog written by David Southworth in our Education team.

9th April - SMILE Mission

Launching on a Vega-C rocket no earlier than 9 April (07:29 – UK-time) from Europe’s spaceport in French Guiana, the SMILE mission (Solar wind Magnetosphere Ionosphere Link Explorer) is a joint venture between the European Space Agency and the Chinese Academy of Sciences. SMILE will have a highly elliptical orbit around the Earth from where it will use four science instruments [SXI (Soft X-ray Imager), UVI (Ultraviolet Imager), LIA (Light Ion Analyser) and MAG (Magnetometer)] to study how Earth responds to the solar wind from the Sun. This will improve our understanding of solar storms, geomagnetic storms, and the science of space weather, filling a gap in our understanding of the Solar System and helping to keep our technology and astronauts safe in the future. Most other similar missions have been ‘detail-oriented’ missions looking at local processes and individual space weather events. SMILE is the opposite - thanks to its wide-field X-ray and ultraviolet vision, it will be the first mission to get a truly global picture of the interaction between the Sun and Earth.

19^th April – Moon and Venus close in the sky

The Moon will be in conjunction (sharing the same right ascension – coordinate) with Venus on the morning of 19 April and they’ll appear relatively close together. But in the daytime sky, you won’t be able to spot them at this time. Instead look towards the west as the Sun begins to set to spot Venus sitting below the very thin waxing crescent moon. Being one of Earth’s closest neighbours and due to its thick reflective atmosphere, Venus will appear like a bright shining star. The duo will be close to the horizon when they become visible so be sure to have a clear view of the western horizon to have a better chance of spotting them. By 21:00 Venus will begin setting so be sure to catch them before then. They should be visible to the naked eye, but you’ll need to find the sweet spot of it being dark enough to spot their light vs. it being early enough that they’re still high enough above the horizon to easily see. Check out the astronomical phenomena blog linked above to find out more about close approaches and conjunctions and other astronomical phenomena.

22nd April – Moon and Jupiter close in the sky

The waxing crescent moon will be observable near Jupiter in the southwest during the evening of 22 April – appearing as the Sun begins to set. The Moon will be in conjunction (sharing the same right ascension – coordinate) with Jupiter later that evening and the pair will appear at their closest approach to each other a short time after midnight, but they’ll be closer to the western horizon at this time and much lower in the sky. Begin looking for them around 20:00 when they’ll easily be visible nice and high in the southwest and if you can wait up until around midnight face towards the west where you’ll be able to spot them at their closest. Jupiter will appear diagonally to the bottom left of our lunar neighbour and both will be observable with the naked eye. Check out the astronomical phenomena blog linked above to find out more about close approaches and conjunctions and other astronomical phenomena.

No Earlier than April - Starship Flight 12

Starship is made up of the Super Heavy booster – a first stage rocket with 33 of SpaceX’s raptor engines, and on top of that sits the upper stage - rather confusingly also called Starship (which hosts 6 engines). And when its fully developed, this launch vehicle will be a completely reusable rocket – both first and second stages. A modified version of Starship is also currently planned to land astronauts on the Moon with the (now) Artemis IV mission. Starship is due to launch on its twelfth test flight no earlier than April 2026 (pushed back from March) from SpaceX’s launch facility, Starbase in Boca Chica, Texas, United States. This flight will be the first flight of version 3 of Starship as both the Starship spacecraft and Super Heavy booster have received significant modifications that will allow it to demonstrate some of the core capabilities that will be needed for Artemis Program lander. It will also be the first flight from Starbase Pad 2 – the newly built second orbital launch pad at SpaceX's launch facility in Starbase. Find out more about Starship and SpaceX’s other rocketry achievements in our SpaceX – the world’s rocket giant blog by Ed Kellond-Turner in our Education team.