Tuesday, February 28, 2017
Ladybugs swarm because they're looking for a warm place to hibernate for winter. They hibernate in clusters. When one of them finds a suitable place, it releases a pheromone that attracts a couple gazillion more of them. In fact, the pheromone can keep the ladybugs coming back year after year.
Monday, February 27, 2017
Star HR 8799 was born about the same time as humanity's ancestors — 60 million years ago, after the dinosaurs went extinct and the age of animals that would lead to our evolution was just beginning here on Earth. It's 129 light years away from us, tucked toward the front legs of the constellation Pegasus. It's so close and so brilliant (five times brighter than our own sun) that on a clear night it can easily be spotted by the naked eye.
In 2008, scientists discovered three planetary companions circling within a dusty disk that surrounds the star, just as the nine planets of our solar system are encircled by the Kuiper belt. And they took a picture. It tied for the first direct image ever taken of planets outside our celestial neighborhood.
Further observation uncovered another planet. And now, we can watch all four in motion.
This three-second animation is the result of seven years of work by Jason Wang, an astronomy graduate student at the University of California, who compiled dozens of images taken by the W.M. Keck observatory in Hawaii to create the digital equivalent of a flip book.
The black circle at the middle is a result of the device used to block the light from the star so that scientists could detect the much fainter gleam of its nearby planets.
The four glowing globes that orbit it are HR 8799's planets. This animation does not show their full orbits — the planets are so far from their star that it would take more than four centuries to create that video.
But this is a snapshot of four alien worlds orbiting a distant sun. And that's pretty incredible.
Story via WP:https://www.washingtonpost.com/news/speaking-of-science/wp/2017/01/27/watch-four-alien-worlds-orbit-a-distant-star/?utm_term=.2c73e8bc894b
For 360 degrees, a view along the plane of the ecliptic is captured in this remarkable panorama, with seven planets in a starry sky. The mosaic was constructed using images taken during January 24-26, from Nacpan Beach, El Nido in Palawan, Philippines. It covers the eastern horizon (left) in dark early morning hours and the western horizon in evening skies. While the ecliptic runs along the middle traced by a faint band of zodiacal light, the Milky Way also cuts at angles through the frame.
Clouds and the Moon join fleeting planet Mercury in the east. Yellowish Saturn, bright star Antares, and Jupiter lie near the ecliptic farther right. Hugging the ecliptic near center are Leo's alpha star Regulus and star cluster M44. The evening planets gathered along the ecliptic above the western horizon, are faint Uranus, ruddy Mars, brilliant Venus, and even fainter Neptune.
Image and info via APODhttps://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Tunç Tezel (TWAN)
Saturday, February 25, 2017
A new kind of bioluminescent sensor causes individual brain cells to imitate fireflies and glow in the dark.
The probe, which was developed by a team of Vanderbilt scientists, is a genetically modified form of luciferase, the enzyme that a number of other species including fireflies use to produce light. It is described in a paper published in the journal Nature Communications.
The scientists created the technique as a new and improved method for tracking the interactions within large neural networks in the brain.
“For a long time neuroscientists relied on electrical techniques for recording the activity of neurons. These are very good at monitoring individual neurons but are limited to small numbers of neurons. The new wave is to use optical techniques to record the activity of hundreds of neurons at the same time,” said Carl Johnson, Stevenson Professor of Biological Sciences, who headed the effort.
“Most of the efforts in optical recording use fluorescence, but this requires a strong external light source which can cause the tissue to heat up and can interfere with some biological processes, particularly those that are light sensitive,” he said.
Individual neuron glowing with bioluminescent light produced by a new genetically engineered sensor. (Johnson Lab / Vanderbilt University)
How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder, with its square appearance the result of our vantage point in viewing the cylinder from the side. Were IC 4406 viewed from the top, it would likely look similar to the Ring Nebula.
This representative-color picture is a composite made by combining images taken by the Hubble Space Telescope in 2001 and 2002. Hot gas flows out the ends of the cylinder, while filaments of dark dust and molecular gas lace the bounding walls. The star primarily responsible for this interstellar sculpture can be found in the planetary nebula's center. In a few million years, the only thing left visible in IC 4406 will be a fading white dwarf star.
Image & info via APODhttps://apod.nasa.gov/apod/astropix.html
Image Credit: C. R. O'Dell (Vanderbilt U.) et al., Hubble Heritage Team, NASA