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World’s first dual- frequency radar satellite
Can trees tell when the summer solstice occurs?
Coffee Table Science
June 25, 2025
Welcome to this edition of Over a Cup of Coffee!
World’s first dual- frequency radar satellite
NASA and ISRO are set to launch the NISAR satellite, the world's first dual-frequency radar satellite. This ambitious $1.5 billion Earth-observation mission promises to revolutionize how we monitor planetary changes. The NISAR (NASA-ISRO Synthetic Aperture Radar) satellite is set to launch this July from India's Satish Dhawan Space Centre.
This groundbreaking mission will provide unprecedented, centimeter-level precision in monitoring Earth's surface, offering clear data day or night, and regardless of weather conditions.
Most Earth-observing satellites need sunlight, limiting their use to clear, daytime conditions. This leaves gaps in data for cloudy regions or during nighttime. The NISAR satellite solves this with its advanced Synthetic Aperture Radar (SAR) system.
SAR, initially a military technology, actively sends and receives radar signals, allowing it to image Earth's surface with continuous, all-weather capability. This means more accurate and timely insights into environmental changes, natural disasters, and agricultural developments, day or night, rain or shine.
NISAR is the first satellite to carry dual-frequency radars and represents the first joint hardware Earth observation venture for NASA and ISRO. Its open data policy will provide free access to high-resolution images and insights for scientists and agencies globally.
Weighing almost three tonnes and equipped with a massive 12-meter radar antenna, NISAR is designed to provide near-real-time data on critical issues like agricultural trends, climate shifts, natural disasters, and environmental changes. Its insights are expected to benefit scientists, farmers, and disaster-response teams worldwide, making it one of the most anticipated Earth science missions in recent memory.
The insights were published in NASA.
A new study has found that every year, a tiny species completes a challenging 620-mile (1,000-kilometer) nighttime migration, navigating in a manner previously unique to humans and migratory birds.
The Bogong moth (Agrotis infusa), an Australian native, is a fully nocturnal species with an adult wingspan of around 2 inches. Each spring, Bogong moths escape the heat by migrating from southeastern Australia to cool caves in the Australian Alps, entering a dormant state. They then return in the fall to mate and die. Researchers replicated this journey in the lab, discovering that the moths use the starry night sky to navigate.
The researchers captured the moths using a light trap and glued them with a very thin rod made up of tungsten on their back. The researchers then attached that rod to a longer tungsten rod, enabling each moth to fly in any direction.
An optical sensor then recorded the insect's heading relative to north every five seconds. They observed that every moth flew in its inherited migratory direction. What's particularly interesting is that the moths flew in the precise direction needed for their journey: south to reach the caves in spring, and north to depart from them in autumn.
These exciting findings enhance scientists' understanding of how insects travel vast distances across continents. Findings also show the moths can navigate correctly despite the stars shifting across the night sky. What makes this insect migration even more astonishing is that different generations undertake the journey annually, with no prior generation to guide them.
The findings were published in the journal Nature.
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A new star has exploded and is visible from North America
A "new star" has appeared in the constellation Lupus, visible to the naked eye from parts of North America. This unexpected stellar explosion occurred within the Milky Way.
Astronomers at Ohio State University's All-Sky Automated Survey for Supernovae first detected the new point of light on June 12. It initially had an apparent magnitude of +8.7, making it too dim for the naked eye. Scientists then analyzed the object's light, concluding it's likely a classical nova—a massive stellar explosion that briefly shines brightly. On June 16, it was officially designated V462 Lupi.
By June 18, V462 Lupi had brightened to an apparent magnitude of +5.7, making it just visible to the naked eye. This means it's now approximately 4 million times brighter than its incredibly faint progenitor star was before June 12.
V462 Lupi, located in the southern Lupus constellation, is best viewed from the Southern Hemisphere. However, it's also visible near the southern horizon in North America just after sunset, with sightings reported from Arizona to Lake Superior. You might spot it with the naked eye, but a telescope or stargazing binoculars will make it easier to see, especially from the U.S. or if its brightness fades soon.
Unlike supernovae, which destroy stars, a nova only affects a star's outer layer. Classical novas like V462 Lupi occur in binary systems where a massive white dwarf star siphons material from its larger partner. When sufficient material accumulates on the dwarf, pressure triggers an explosion, burning the stolen gas and emitting bright light pulses towards Earth. Since V462 Lupi's current outburst is its first recorded appearance, we don't know if or when it will explode again.
The insights were published in Sky & Telescope.
Can trees tell when the summer solstice occurs?
Humans have long celebrated the summer solstice with rituals, but studies now reveal plants also recognize June 21 as a crucial cue. It's been proposed that trees might use the summer solstice as a crucial marker for their growth and reproductive cycles, essentially treating it as a calendar reminder.
Satellite data and greenhouse studies show that warmer pre-solstice temperatures trigger earlier autumn leaf browning, while warmer post-solstice temperatures delay it. This allows a longer green-to-brown leaf transition, enabling trees to extend photosynthesis during prolonged warm conditions and capitalize on favorable temperatures.
However, it's more widely accepted that plants use the solstice to synchronize reproduction. Many plants, particularly temperate trees, exhibit masting, where seed production varies drastically year-to-year.
For instance, a large European beech can produce hundreds of thousands of seeds in a "mast event" but none in other years. Scientists have long been puzzled by how European beech trees synchronize their mast events, with seed production consistently tied to temperatures in late June and early July, regardless of their location. The question remains: how do these trees know the date?
The research showed that beech trees across Europe use the solstice as a seasonal marker, sensing temperature changes simultaneously as days shorten post-solstice. This enables beech trees to maximize the synchrony of their reproduction, either investing in a mast year during warm temperatures or foregoing it when temperatures are low.
Evidence for this phenomenon comes from observations in dozens of European forests. Studies on plant circadian rhythms reveal molecular mechanisms that detect subtle day-length changes, enabling extraordinary synchronized reproduction. If the weather remains warm this month, beech trees across the UK and much of northern and central Europe are likely to produce heavy seed crops next autumn.
The insights were published in The Conversation.
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Adya
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