Whenever I think of meteor showers, I think years back to a perfect moment. I was crashed out with friends on a sandy beach alongside the Tuolumne River during a 2-day white water rafting trip. We were enjoying a balmy summer night as we lay on top of our sleeping bags, looking up at the amazing display of stars in a sky free of city light pollution. As we chatted and sipped wine, I noticed an incredibly bright “shooting star” flaming across the sky. Then another. And another. I’d never seen so many “shooting stars” (meteors). I stayed up most of the night to watch the nearly continuous celestial display. When I got home, I learned that it was actually an annual event – the prolific Perseid meteor shower.
Meteor showers can appear anywhere in the sky. But if you trace their path, the meteors appear to come from the same region in the sky. In the case of the Perseids, the meteors appear to originate from the constellation Perseus.
Meteor showers are caused by comets. As a comet orbits the Sun, it sheds a debris stream of ice and dust along its orbit. When Earth travels through this cloud of debris, the bits of interplanetary rock strike the Earth’s upper atmosphere where they are heated by friction and ignited.
The Perseid meteor shower comes from the Swift-Tuttle, a huge comet with a nucleus of 26 km and meteoroids hitting our atmosphere at 132,000 mph. According to new research by NASA, the Perseids are the most prolific meteor shower. The number of resulting meteors can top 100 per hour.
Although the meteor shower is active for several days, the peak will happen tonight through the early hours of tomorrow morning. A crescent moon will set shortly after midnight, leaving the skies dark for optimal viewing until pre-dawn. You just need to search out a secluded spot away from the glow of city lights, like a state or city park, then lie back and enjoy the show.
Affiliated with PBS and NPR, KQED public media has served Northern California for over 50 years. In February 2007, KQED started its large multimedia series, QUEST. QUEST explores the latest science and environmental news, trends and issues. It has reached more than 60 million viewers and listeners through television, radio and the Web. QUEST mainly covers stories that have a San Francisco Bay Area focus.
Now QUEST is expanding to a national audience, joining with QUEST partner organizations from North Carolina, Nebraska, Ohio, Wisconsin and the Northwest (Seattle). Together they have just received a $2.5 million grant from the National Science Foundation for a two-year collaborative multimedia science reporting initiative called QUEST Beyond Local.
The new series will focus on the “Science of Sustainability” in six key areas: climate, food, energy, water, health and biodiversity. Content will be developed for television, radio, the Web, educational assets and community outreach.
QUEST Beyond Local is scheduled to start broadcasting new content this summer. Stay tuned for my upcoming articles as a contributing author. Meanwhile, my health beat coverage has just moved to KQED Science.
Scientists will talk about their latest research findings on how the earth’s climate is changing, from the arctic to the rainforest. Participating speakers will address critical questions: What happens when the permafrost thaws? What do computer models predict about our future climate – floods, droughts, hurricanes and heat waves? What role do our forests play in carbon absorption? What kind of carbon tax might actually work?
Come find out what to expect and if there is anything you can do about it!
When viewed from the Earth, a solar eclipse happens when the Moon passes between the Sun and Earth so the Moon blocks the Sun. If the Moon only blocks part of the Sun, then it is a partial solar eclipse. If the Sun is fully obscured by the Moon, then it is a total solar eclipse. Total eclipses are rare at any one location, because the Moon fully blocks the Sun along only a narrow path on the Earth’s surface traced by the Moon’s shadow.
According to the National Aeronautics and Space Administration (NASA), a partial solar eclipse will occur on May 20, 2012. This is the first solar eclipse to happen in the United States since 1994. In San Francisco, this eclipse will begin at 5:15 pm and end at 7:40 pm. The maximum eclipse will occur at 6:32 pm when 85% of the sun will be obscured. This partial eclipse will look the like the Moon has a ring of fire surrounding it.
Although it is tempting, you shouldn’t view a solar eclipse with the naked eye. Your eye-lens will concentrate the sun’s light onto your retina, and this can cause permanent eye damage. You can safely view a solar eclipse wearing inexpensive solar glasses (with a “CE” label), which have filters that block out 99.99% of the sun’s light and 100% of the harmful ultraviolet rays. Don’t have solar glasses? You can also safely view a solar eclipse by indirect projection – projecting the image of the sun onto a white piece of paper using a pinhole camera. The San Francisco Exploratorium has directions on how to make a pinhole camera.
Looking back, the only school field trip that I remember was our trip to the San Francisco Exploratorium. I enjoyed the fun interactive science exhibits, but what I remember best is the tactile dome. I entered into total darkness and spent the next hour feeling, crawling and sliding my way through a 3-D maze. The purpose of the tactile room is to explore a disorienting world in which you can only rely on touch. For a kid, the challenge is to do that as quickly as possible.
However, that field trip is tame compared to what Kara Platoni, Eric Simons, and Casey Miner have in mind. They’ve launched a new podcast, The Field Trip, that broadcasts their real world science adventures. To add a little more intellectual rigor, they also interview an expert guest in their radio studio for each episode. Beginning on May 14, a new episode will air weekly each Monday through June 4.
The stereotypical image of a scientist looks something like Albert Einstein, an older white man with either wild hair or almost none. The media often reinforces this image of a “mad scientist” in a white lab coat. But in reality, scientists are just a diverse group of people that mostly look and act like everyone else.
This scientist stereotype has been informally studied by at least two major scientific laboratories, Fermilab and the Pacific Northwest National Laboratory. About 12 years ago, a group of seventh graders came for a regular field trip to Fermilab. Few young people have ever knowingly met a scientist. So Fermilab had these students draw and describe what they thought a scientist looked like, both before and after going on the tour. While at Fermilab, the students met a diverse selection of real life scientists, including speaking in small groups with a typical white male, a young female and an African American male physicist. Before their field trip, the students mostly drew the stereotypical white man wearing a lab coat. However, their drawings after the tour were much more diverse and casually dressed.
Such studies have inspired a small group of people to demonstrate what a scientist is really like. Also inspired by Science Online 2012, they recently created a website where scientists can post a photograph and short description of themselves. Their hope is to challenge the stereotypical perception of a scientist. If you are a scientist and interested in joining their efforts, you can easily submit your photograph to be uploaded on their “This Is What A Scientist Looks Like” home page. However, I hope everyone enjoys the ever-expanding collection of photographs.
As a medical imaging researcher, I notice when medical imaging technologies are mentioned by popular news media or medical-themed television shows. Lately I’ve been seeing PET imaging mentioned more frequently, including on TV shows like House and Grey’s Anatomy. This probably just reflects the fact that dramatically increasing numbers of PET scans are being performed in real life in clinics and hospitals. So what is PET imaging? Funny that you ask, because I just happen to do research in this field.
In this context, PET stands for Positron Emission Tomography. During a PET scan, a trace amount of biologically-active, radioactive drug is injected into the patient’s vein. The drug localizes somewhere in the patient, depending on the metabolic properties of the selected drug. The drug then emits a positron (anti-particle of the electron), and the positron annihilates with an electron in the patient’s body. The resulting energy forms gamma ray pairs that pass through the patient and are detected by the PET scanner. These detected gamma ray signals are used to create a 3-D volumetric image or picture of the drug’s concentration in the body.
PET imaging technology is unique because it images a patient’s metabolism, whereas most other medical imaging techniques measure anatomical structure. For example, X-ray CT or MRI scans can be used to identify a tumor because they show the patient’s anatomy in detail. However, PET imaging can identify if the tumor is benign or cancerous, by measuring whether or not the tumor takes up the radioactive drug. In reality, you’d really like to know both though — detailed anatomical structure and metabolic function. Recent work has demonstrated the increased clinical diagnostic value of fusing imaging technologies based on function (e.g., PET, SPECT or functional MRI) with those based on structure (e.g., CT, MRI, or ultrasound). As a result, PET and CT scanners are now typically combined into a single gantry system, so that images can be taken from both devices sequentially during a single procedure.
Since PET measures metabolism instead of anatomical structure, it is mostly used to image organs whose size or shape does not indicate whether they are functioning properly, such as the brain or heart. It is also used to diagnose diseases that exhibit an abnormal metabolism, such as cancer.
Stay tuned this week when I discuss some Alzheimer’s research that utilizes PET imaging.