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By European Space Agency
The European Space Agency (ESA) is ready to guide the ESA/NASA Solar Orbiter spacecraft through its closest encounter with Venus so far.
Today’s flyby will be the first to significantly ‘tilt’ the spacecraft’s orbit and allow it to see the Sun’s polar regions, which cannot be seen from Earth.
Studying the Sun’s poles will improve our understanding of solar activity, space weather, and the Sun-Earth connection.
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By European Space Agency
Image: With the festive season approaching, even Earth-observing satellites are getting into the spirit, capturing a stunning compilation of European cities that resemble stars. View the full article
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By NASA
5 Min Read NASA DAVINCI Mission’s Many ‘Firsts’ to Unlock Venus’ Hidden Secrets
The surface of Venus is an inferno with temperatures hot enough to melt lead. This image is a composite of data from NASA’s Magellan spacecraft and Pioneer Venus Orbiter. Credits:
NASA/JPL-Caltech NASA’s DAVINCI — Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging — mission embodies the spirit of innovation and exploration that its namesake, Leonardo da Vinci, was famous for.
Scheduled to launch in the early 2030s, DAVINCI will explore Venus with both a spacecraft and a descent probe. DAVINCI’s probe will be the first in the 21st century to brave Venus’ atmosphere as it descends from above the planet’s clouds down to its surface. Two other missions, NASA’s VERITAS and ESA’s (European Space Agency) Envision, will also explore Venus in the 2030s from the planet’s orbit.
The DAVINCI spacecraft will study Venus’ clouds and highlands during two flybys. It also will release a spherical probe, about 3 feet wide, that will plunge through the planet’s thick atmosphere and corrosive clouds, taking measurements and capturing high-resolution images of the Venusian surface as it descends below the clouds.
Here are some of DAVINCI’s coming “firsts” in Venus exploration:
Exploring Solar System’s One-of-a-Kind Terrain
The DAVINCI mission will be the first to closely explore Alpha Regio, a region known as a “tessera.” So far found only on Venus, where they make up about 8% of the surface, tesserae are highland regions similar in appearance to rugged mountains on Earth. Previous missions discovered these features using radar instruments, but of the many international spacecraft that dove through Venus’ atmosphere between 1966 and 1985, none studied or photographed tesserae.
Thought to be ancient continents, tesserae like Alpha Regio may be among the oldest surfaces on the planet, offering scientists access to rocks that are billions of years old.
By studying these rocks from above Alpha Regio, DAVINCI scientists may learn whether ancient Venus had continents and oceans, and how water may have influenced the surface.
Photographing One of the Oldest Surfaces on Venus
The DAVINCI probe will capture the first close-up views of Alpha Regio with its infrared and optical cameras; these will also be the first photos of the planet’s surface taken in more than 40 years.
With surface temperatures reaching 900° F and air pressure 90 times that of Earth’s, Venus’ harsh environment makes exploration challenging, while its opaque atmosphere obscures direct views. Typically, scientists rely on radar instruments from Earth or Venus-orbiting spacecraft to study its terrain.
But DAVINCI’s probe will descend through the atmosphere and below the clouds for a clear view of the mountains and plains. It will capture images comparable to an airplane’s landing view of Earth’s surface. Scientists will use the photos to compile 3D maps of Alpha Regio that will provide more detail than ever of Venus’ terrain, helping them look for rocks that are usually only made in association with water.
Unveiling Secrets of Venus’ Mysterious Lower Atmosphere
The DAVINCI mission will be the first to analyze the chemical composition of Venus’ lower atmosphere through measurements taken at regular intervals, starting from approximately 90,000 feet above the surface and continuing until just before impact.
This region is critical because it contains gases and chemical compounds that may originate from Venus’ lower clouds, surface, or even subsurface.
For example, sulfur compounds detected here could indicate whether Venusian volcanoes are currently active or were active in the recent past. Noble gases (like helium or xenon), on the other hand, remain chemically inert and maintain stable concentrations, offering invaluable clues about Venus’ ancient history, such as the planet’s past water inventory.
By comparing Venus’ noble gas composition with that of Earth and Mars, scientists can better understand why these planets — despite forming from similar starting materials — evolved into dramatically different worlds.
Moreover, DAVINCI’s measurements of isotopes and trace gases in the lower atmosphere will shed light on Venus’ water history, from ancient times to the present, and the processes that triggered the planet’s extreme greenhouse effect.
State-of-the-Art Technology to Study Venus in Detail
Thanks to modern technology, the DAVINCI probe will be able to do things 1980s-era spacecraft couldn’t.
The descent probe will be better equipped than previous probes to protect the sensitive electronics inside of it, as it will be lined on the inside with high-temperature, multi-layer insulation — layers of advanced ceramic and silica fabrics separated by aluminum sheets.
Venus’ super thick atmosphere will slow the probe’s descent, but a parachute will also be released to slow it down further. Most Earth-friendly parachute fabrics, like nylon, would dissolve in Venus’ sulfuric acid clouds, so DAVINCI will have to use a different type of material than previous Venus missions did: one that’s resistant to acids and five times stronger than steel.
Read More: Old Data Yields New Secrets as NASA’s DAVINCI Preps for Venus Trip
By Lauren Colvin, with Lonnie Shekhtman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator institution for DAVINCI and will perform project management for the mission, provide science instruments, as well as project systems engineering to develop the in-situ probe flight system that will enter the atmosphere of Venus. Goddard also leads the overall science for the mission with an external science team from across the United States. Lockheed Martin Space in Denver, Colorado, will build the carrier/relay spacecraft. DAVINCI is a mission within the Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
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By NASA
As any urban dweller who has lived through a heat wave knows, a shady tree can make all the difference. But what happens when there’s no shade available?
A recent study in Nature Communications used NASA satellite data to identify a major gap in global resilience to climate change: cities in the Global South have far less green space — and therefore less cooling capacity — than cities in the Global North. The terms Global North and Global South were used in the study to distinguish developed countries (mostly in the Northern Hemisphere) from developing nations (mostly in the Southern Hemisphere).
Cities tend to be hotter than nearby rural areas because of the urban heat island effect. Heat-trapping dark surfaces such as sidewalks, buildings, and roads absorb heat from the Sun’s rays, which raises the temperature of the city. Extreme heat poses serious health threats for urban residents, including dehydration, heat stroke, and even death. Though not a cure-all, greenery provides shade and releases moisture into the air, cooling the surroundings.
“Cities can strategically prioritize developing new green spaces in areas that have less green space,” said Christian Braneon, a climate scientist at NASA’s Goddard Institute for Space Studies in New York who was not affiliated with this study. “Satellite data can be really helpful for this.”
The Operational Land Imager (OLI) on the NASA and U.S. Geological Survey’s Landsat 8 satellite captured this natural color image of Sanaa, Yemen, on June 8, 2024. Sanaa, which has a hot, dry climate and little green space, had the second-lowest cooling capacity of 500 cities studied in a paper recently published in the journal Nature Communications. Wanmei Liang, NASA Earth Observatory An international team of researchers led by Yuxiang Li, a doctoral student at Nanjing University, analyzed the 500 largest cities in the world to compare their cooling capacities. They used data from the Landsat 8 satellite, jointly managed by NASA and the U.S. Geological Survey, to determine how effective green space was at cooling each city.
First, they calculated the average land surface temperature for the hottest month of 2018 for each city, as well as the average of the hottest months from 2017 to 2019. Next, the researchers used a metric called the Normalized Difference Vegetation Index (NDVI) to map how much green space each city had. The NDVI relies on the fact that healthy vegetation absorbs red light and reflects infrared light: the ratio of these wavelengths can show the density of healthy vegetation in a given satellite image.
Researchers found that cities in the Global South have just 70% of the greenery-related cooling capacity of cities in the Global North. The green spaces in an average Global South city cool the temperature by about 4.5 F (2.5 C). In an average Global North city, that cooling capacity is 6.5 F (3.6 C). This compounds an existing problem: cities in the South tend to be at lower latitudes (that is, nearer to the Equator), which are predicted to see more heat extremes in the coming years.
“It’s already clear that Global South countries will be impacted by heat waves, rising temperatures, and climatic extremes more than their Global North counterparts,” said Chi Xu, a professor of ecology at Nanjing University and a co-author of the study. The Global South has less capacity to adapt to heat because air conditioning is less common and power outages are more frequent.
Why do cities in the Global South struggle to stay cool? Cities in the Global South tend to have less green space than cities in the Global North. This mirrors studies of the disparities within cities, sometimes referred to as the “luxury effect”: wealthier neighborhoods tend to have more green space than poorer neighborhoods. “Wealthier cities also have more urban green spaces than the poorest cities,” Chi said.
It’s unlikely that urban planners can close the gap between the study’s worst-performing city (Mogadishu, Somalia) and the best-performing one (Charlotte, North Carolina).
Mogadishu is a dense city with a dry climate that limits vegetation growth. Still, there’s a lot that each city can learn from its neighbors. Within a given region, the researchers identified the city with the greatest cooling capacity and used that as a goal. They calculated the difference between the best-performing city in the region and every city nearby to get the potential additional cooling capacity. They found that cities’ average cooling capacity could be increased substantially — to as much as 18 F (10 C) — by systematically increasing green space quantity and quality.
“How you utilize green space is really going to vary depending on the climate and the urban environment you’re focused on,” said Braneon, whose research at NASA focuses on climate change and urban planning.
Greener cities in the U.S. and Canada have lower population densities. However, fewer people per square mile isn’t necessarily good for the environment: residents in low-density cities rely more on cars, and their houses tend to be bigger and less efficient. Braneon noted that there’s a suite of solutions beyond just planting trees or designating parks: Cities can increase cooling capacity by creating water bodies, seeding green roofs, and painting roofs or pavement lighter colors to reflect more light.
With a global study like this, urban planners can compare strategies for cities within the same region or with similar densities. “For newly urbanized areas that aren’t completely built out, there’s a lot of room to still change the design,” Braneon said.
By Madeleine Gregory
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Nov 26, 2024 Editor Rob Garner Contact Rob Garner rob.garner@nasa.gov Location Goddard Space Flight Center Related Terms
Climate Change Earth Goddard Institute for Space Studies Goddard Space Flight Center Landsat Landsat 8 / LDCM (Landsat Data Continuity Mission) View the full article
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