Bsuobservatory - Bridgewater State University Observatory

2023 October 10

Hidden Orion from Webb Image Credit & License: NASA, ESA, CSA, JWST; Processing: M. McCaughrean & S. Pearson

Explanation: The Great Nebula in Orion has hidden stars. To the unaided eye in visible light, it appears as a small fuzzy patch in the constellation of Orion. But this image was taken by the Webb Space Telescope in a representative-color composite of red and very near infrared light. It confirms with impressive detail that the Orion Nebula is a busy neighborhood of young stars, hot gas, and dark dust. The rollover image shows the same image in representative colors further into the near infrared. The power behind much of the Orion Nebula (M42) is the Trapezium - a cluster of bright stars near the nebula’s center. The diffuse and filamentary glow surrounding the bright stars is mostly heated interstellar dust. Detailed inspection of these images shows an unexpectedly large number of Jupiter-Mass Binary Objects (JuMBOs), pairs of Jupiter-mass objects which might give a clue to how stars are forming. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next few million years.

∞ Source: apod.nasa.gov/apod/ap231010.html

Six Answers to Questions You’re Too Embarrassed to Ask about the Hottest Year on Record

You may have seen the news that 2023 was the hottest year in NASA’s record, continuing a trend of warming global temperatures. But have you ever wondered what in the world that actually means and how we know?

We talked to some of our climate scientists to get clarity on what a temperature record is, what happened in 2023, and what we can expect to happen in the future… so you don’t have to!

1. Why was 2023 the warmest year on record?

The short answer: Human activities. The release of greenhouse gases like carbon dioxide and methane into the atmosphere trap more heat near Earth’s surface, raising global temperatures. This is responsible for the decades-long warming trend we’re living through.

But this year’s record wasn’t just because of human activities. The last few years, we’ve been experiencing the cooler phase of a natural pattern of Pacific Ocean temperatures called the El Niño Southern Oscillation (ENSO). This phase, known as La Niña, tends to cool temperatures slightly around the world. In mid-2023, we started to shift into the warmer phase, known as El Niño. The shift ENSO brought, combined with overall human-driven warming and other factors we’re continuing to study, pushed 2023 to a new record high temperature.

2. So will every year be a record now?

Almost certainly not. Although the overall trend in annual temperatures is warmer, there’s some year-to-year variation, like ENSO we mentioned above.

Think about Texas and Minnesota. On the whole, Texas is warmer than Minnesota. But some days, stormy weather could bring cooler temperatures to Texas while Minnesota is suffering through a local heat wave. On those days, the weather in Minnesota could be warmer than the weather in Texas. That doesn’t mean Minnesota is warmer than Texas overall; we’re just experiencing a little short-term variation.

Something similar happens with global annual temperatures. The globe will naturally shift back to La Niña in the next few years, bringing a slight cooling effect. Because of human carbon emissions, current La Niña years will be warmer than La Niña years were in the past, but they’ll likely still be cooler than current El Niño years.

3. What do we mean by “on record”?

Technically, NASA’s global temperature record starts in 1880. NASA didn’t exist back then, but temperature data were being collected by sailing ships, weather stations, and scientists in enough places around the world to reconstruct a global average temperature. We use those data and our modern techniques to calculate the average.

We start in 1880, because that’s when thermometers and other instruments became technologically advanced and widespread enough to reliably measure and calculate a global average. Today, we make those calculations based on millions of measurements taken from weather stations and Antarctic research stations on land, and ships and ocean buoys at sea. So, we can confidently say 2023 is the warmest year in the last century and a half.

However, we actually have a really good idea of what global climate looked like for tens of thousands of years before 1880, relying on other, indirect ways of measuring temperature. We can look at tree rings or cores drilled from ice sheets to reconstruct Earth’s more ancient climate. These measurements affirm that current warming on Earth is happening at an unprecedented speed.

4. Why does a space agency keep a record of Earth’s temperature?

It’s literally our job! When NASA was formed in 1958, our original charter called for “the expansion of human knowledge of phenomena in the atmosphere and space.” Our very first space missions uncovered surprises about Earth, and we’ve been using the vantage point of space to study our home planet ever since. Right now, we have a fleet of more than 20 spacecraft monitoring Earth and its systems.

Why we created our specific surface temperature record – known as GISTEMP – actually starts about 25 million miles away on the planet Venus. In the 1960s and 70s, researchers discovered that a thick atmosphere of clouds and carbon dioxide was responsible for Venus’ scorchingly hot temperatures.

Dr. James Hansen was a scientist at the Goddard Institute for Space Studies in New York, studying Venus. He realized that the greenhouse effect cooking Venus’ surface could happen on Earth, too, especially as human activities were pumping carbon dioxide into our atmosphere.

He started creating computer models to see what would happen to Earth’s climate as more carbon dioxide entered the atmosphere. As he did, he needed a way to check his models – a record of temperatures at Earth’s surface over time, to see if the planet was indeed warming along with increased atmospheric carbon. It was, and is, and NASA’s temperature record was born.

5. If last year was record hot, why wasn’t it very hot where I live?

The temperature record is a global average, so not everywhere on Earth experienced record heat. Local differences in weather patterns can influence individual locations to be hotter or colder than the globe overall, but when we average it out, 2023 was the hottest year.

Just because you didn’t feel record heat this year, doesn’t mean you didn’t experience the effects of a warming climate. 2023 saw a busy Atlantic hurricane season, low Arctic sea ice, raging wildfires in Canada, heat waves in the U.S. and Australia, and more.

And these effects don’t stay in one place. For example, unusually hot and intense fires in Canada sent smoke swirling across the entire North American continent, triggering some of the worst air quality in decades in many American cities. Melting ice at Earth’s poles drives rising sea levels on coasts thousands of miles away.

6. Speaking of which, why is the Arctic – one of the coldest places on Earth – red on this temperature map?

Our global temperature record doesn’t actually track absolute temperatures. Instead, we track temperature anomalies, which are basically just deviations from the norm. Our baseline is an average of the temperatures from 1951-1980, and we compare how much Earth’s temperature has changed since then. 

Why focus on anomalies, rather than absolutes? Let’s say you want to track if apples these days are generally larger, smaller, or the same size as they were 20 years ago. In other words, you want to track the change over time.

Apples grown in Florida are generally larger than apples grown in Alaska. Like, in real life, how Floridian temperatures are generally much higher than Alaskan temperatures. So how do you track the change in apple sizes from apples grown all over the world while still accounting for their different baseline weights? 

By focusing on the difference within each area rather than the absolute weights. So in our map, the Arctic isn’t red because it’s hotter than Bermuda. It’s red because it’s gotten relatively much warmer than Bermuda has in the same time frame.

Want to learn more about climate change? Dig into the data at climate.nasa.gov.

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Astronomy Word of the Day

The Magellanic Clouds are two small, irregular dwarf galaxies outside of the Milky Way. These two galaxies are visible in the skies of the southern hemisphere, close to the South Celestial Pole, so they don't appear to set!

Image: https://aaa.org/.../01/southern-skies-the-magellanic-clouds/

Happy Monday!

Today's picture of the day was taken by Matthew Dominick from the ISS! The image shows a giant jet lightning, which is a new discovery (only 23 years!) and associated with thunderstorms. While regular lightning travels between the ground and the clouds, giant jet lightning bursts upwards.

Video of the Day!

Hubble has discovered that Jupiter’s red spot - a storm larger than Earth - is wobbling!

Today's word of the day is "earthshine" which is when the Earth reflects the Sun's light so that it makes the dark side of the moon glow! Super cool.

Image credit: Abhijit Juvekar

If galaxies could talk, we’d want to ask for this galaxy’s skincare routine!

Meet I Zwicky 18, a galaxy lying 60 million light-years away in the constellation Ursa Major.

The bluish-white knots in the center are regions where stars are forming at a rapid rate. These large hubs of stellar creation and the lack of heavy elements in the surrounding gas caused astronomers to think that this dwarf irregular galaxy was very young, since it resembles galaxies in the early universe.

However, the Hubble Space Telescope revealed that I Zwicky 18 is more mature than it first appears. Hubble found faint, older stars within the galaxy, indicating that I Zwicky 18 has been forming stars for more than a billion years.

Credit: NASA, ESA, A. Aloisi (Space Telescope Science Institute and European Space Agency).

ALT TEXT: A bright white and blue oval-shaped area takes up most of the view and is largely centered. Cloud-like wisps of blue material surround the bright-white center, forming a fluffy wreath-like shape. The fluffy material begins as light blue near the center and gradually darkens moving outward. Stars, seen as many bright white and yellow small points of light, are densely grouped in the white and light blue region, forming two roughly circular clumps, one in the upper left and one in the lower right. The corners of the image are dark and mostly empty, with a few larger, fuzzy yellow points of light scattered infrequently throughout.

Happy fun fact Friday!

Did you know that the largest canyon system in the solar system is Valles Marineris on Mars? The image shows the Valles Marineris compared to the US coast to coast and the Grand Canyon!

Source: NASA