NASA on April 21–22 unveiled and confirmed completion of the Nancy Grace Roman Space Telescope at Goddard Space Flight Center in Greenbelt, Maryland. The 2.4‑metre mirror observatory, named for NASA’s first chief astronomer, will survey vast swathes of sky with a field of view at least 100 times larger than Hubble’s. Its Wide Field Instrument (a 300‑megapixel visible-to-near‑infrared imager and slitless spectrometer) and a technology demonstration coronagraph aim to map dark matter and dark energy, discover tens of thousands of exoplanets via gravitational microlensing, and catch transient events. NASA says Roman was finished ahead of schedule and under budget and will be shipped to Kennedy Space Center for launch aboard a SpaceX Falcon Heavy as early as September 2026 (with later contingency windows). The mission is expected to return more data in its first year than Hubble has over decades, enabling wide-area surveys that will drive target selection for JWST, Euclid and ground observatories such as the Vera Rubin Observatory.

On the evening of April 22, 2026, observers across wide swathes of the globe can spot a close visual pairing of the Moon and Jupiter in the western sky shortly after sunset. The Moon, waxing and approaching first quarter, will sit roughly 3 degrees above and to the right of Jupiter; the pair will be visible about 45 minutes after local sunset and will appear about two-thirds of the way from the horizon toward the zenith. Jupiter remains one of the brightest nighttime objects (around magnitude –2.1), easily seen with the naked eye; binoculars or a small telescope will reveal at least three Galilean moons. Timing of satellite events will vary by time zone — for example, on the U.S. east coast Io disappears behind Jupiter at about 10:39 p.m. EDT and Europa emerges from eclipse at about 11:36 p.m. EDT. The alignment sits near the Gemini constellation, with Castor and Pollux nearby. Skywatchers are advised to find an open western view and, for photography, to steady a phone or use a tripod and modest exposure settings to capture both bodies without overexposing the Moon.

A federal judge on April 21 issued a preliminary injunction blocking a suite of Trump administration permitting policies that renewable energy groups say have stymied new wind and solar projects across the United States. Chief U.S. District Judge Denise J. Casper found the Interior Department and other agencies likely acted unlawfully by adopting measures — including a memorandum requiring elevated three‑appointee signoffs for nearly every step of wind and solar permitting, stricter interpretations of offshore authorities, a sector‑wide permit freeze and rules disadvantaging “capacity dense” projects — that prompted developers to cancel or delay projects. The injunction, sought by nine regional industry associations including RENEW Northeast, Alliance for Clean Energy New York, the Southern Renewable Energy Association and Interwest, applies to members of those groups while litigation proceeds. The Interior Department declined to comment on the case. The ruling follows several recent judicial setbacks to the administration’s attempts to curb offshore wind and comes as the White House has pushed fossil fuel production and used measures such as the Defense Production Act to support oil, coal and gas.

The annual Lyrid meteor shower peaked on the night of April 21–22, 2026, producing bright, fast meteors visible across much of the Northern Hemisphere. Earth passed through debris left by long‑period comet C/1861 G1 (Thatcher), whose 415‑year orbit replenishes the stream that creates the display each mid‑April. Observers reported typical rates of about 10–20 meteors per hour under dark skies, with occasional bright fireballs; historical surges have pushed counts far higher. A slim waxing crescent moon and widespread clear weather in many regions improved viewing conditions. Amateur and professional photographers documented colorful streaks and short dust trains from ground locations in North America, Europe and Asia, while NASA astronaut Jessica Meir aboard the International Space Station photographed meteors ablating above Earth’s limb, offering rare orbital perspectives. Networks such as the Global Meteor Network and spaceborne imagery helped corroborate fireball activity; the shower remains active through late April and is followed by the stronger Eta Aquariids in early May.

Researchers at NASA’s Jet Propulsion Laboratory report that fungal spores recovered from spacecraft assembly cleanrooms can survive a suite of simulated space and Martian conditions, raising fresh concerns about forward contamination. In experiments reported in Applied and Environmental Microbiology (April 2026), scientists collected 27 fungal strains from facilities used in the Mars 2020 program and exposed their asexual spores (conidia) to intense ultraviolet radiation, months-long ionizing radiation doses, low pressure, Mars-like regolith, and extreme cold. Most strains survived UV exposure; one species, Aspergillus calidoustus, withstood UV, prolonged ionizing radiation and low-pressure, low-temperature conditions that mimic a mission to Mars. Only prolonged exposure to a combination of very high radiation and extreme cold reliably killed it. The team, led by Kasthuri Venkateswaran of JPL, says the findings do not prove Mars contamination will occur but highlight fungi as an underappreciated gap in planetary protection protocols. The results also note potential human-health implications for astronaut safety and call for updated sterilisation and monitoring standards for future robotic and crewed missions.