“Most Distant Supermassive Black Hole Discovered”

Right now Chandra is studying a galaxy in Ursa Major. Nearby in this dwarf galaxy, stars are forming at a furious rate! The galaxy, known as I Zwicky 18, is located about 59 million light years from Earth.

The constellation name, Ursa Major, means Big Bear. The “bear” association has its origins in two major civilizations which saw two very different bears in the sky. The Greeks who named this constellation (later translated into the Latin name we use today) thought that the stars outlined the shape of a bear walking about on its clawed feet. It and its smaller companion, Ursa Minor were said to be the prey of Boötes and his hunting dogs. The long cat-like tail on the bears was part of the ancient pattern and is somewhat of a mystery. A story in Ovid tried to offer an explanation. In that myth, Zeus fell in love with Callisto. Hera changed her into a bear out of jealousy. Her son Arcus (the namesake of Arcturus, the alternate name for the constellation Boötes) came upon her in the forest and she ran to greet him. Not knowing the bear was his mother, he was about to kill her. To save her, Zeus turned Arcus into a smaller bear, grabbed them both by their tails and flung them into the sky, causing their tails to be stretched. A number of Native American tribes also referred to this constellation as a bear, but with a clever addition. In their description of these stars, the bear is the same, but without the “tail”. Instead, those three stars are three hopeful hunters, and the middle one is carrying a cooking pot for cooking up the bear. Johannes Hevelius’ Ursa Major from Uranographia (1690) The most common pattern seen in this constellation is composed of a smaller group of the brightest stars (called an asterism) that outline the Big Dipper. This name comes from many different cultures which have seen in these stars a long handled spoon, often used for dipping water for drinking. Others call this pattern a plow, seeing instead of a dipper, an old-style, ox-pulled farm plow. The plow pattern, pulled by oxen, is the shape referenced in the myth of the Triones, the oxen and plow driven by Bootes the herder. The Egyptians and the Chinese saw different associations. Even in relatively more modern times, early European civilizations continued to invent new meanings for this pattern.

Constellation map from: http://www.lunarplanner.com/StarsProperMotion/UrsaMajor/

For a list of objects in Ursa Major that Chandra has observed and article, see link:  http://chandra.si.edu/photo/constellations/ursamajor.html

Sensor to monitor orbital debris outside space station

The International Space Station isn’t the only spacecraft orbiting the Earth. In fact, it is accompanied by the Hubble Space Telescope, satellites within the Earth Observing System, and more than 1,000 other operational spacecraft and CubeSats. In addition to spacecraft, bits of orbital debris - human-made objects no longer serving a purpose in space - are also in orbit.

With an estimated more than 100 million pieces of orbital debris measuring smaller than one centimeter currently in Earth’s orbit, they can be too small to track, but many are large enough to cause damage to operational spacecraft.

The space station has orbital debris shields in place to protect from debris less than 1.5 centimeters in size. Larger debris pieces are tracked by ground control, and if needed, the space station thrusters can be used to safely move station away from the debris.

The Space Debris Sensor (SDS) will monitor the small debris environment around the space station for two to three years, recording instances of debris between the sizes of .05mm to.5mm. Objects larger than 3 mm are monitored from the ground. It will launch to station in the trunk of a SpaceX Dragon during a resupply mission no earlier than Dec. 12.

Orbital debris as small as .3mm may pose a danger to human spaceflight and robotic missions.

“Debris this small has the potential to damage exposed thermal protection systems, spacesuits, windows and unshielded sensitive equipment,” said Joseph Hamilton, the project’s principal investigator. “On the space station, it can create sharp edges on handholds along the path of spacewalkers, which can also cause damage to the suits.”

Once it is mounted on the exterior of the Columbus module aboard the space station, the sensor will provide near-real-time impact detection and recording capabilities.

Using a three-layered acoustic system, the SDS characterizes the size, speed, direction and density of these small particles. The first two layers are meant to be penetrated by the debris. This dual-film system provides the time, location and speed of the debris, while the final layer - a Lexan backstop - provides the density of the object.

The first and second layers of the SDS are identical, equipped with acoustic sensors and .075mm wide resistive lines. If a piece of debris damages the first layer, it cuts through one or more of the resistive lines before impacting and going through the second layer. Finally, the debris hits the backstop plate.

Although the backstop won’t be used to return any of the collected samples, combined with the first two layers, it gives researchers valuable data about the debris that impacts the SDS while in orbit.

“The backstop has sensors to measure how hard it is hit to estimate the kinetic energy of the impacting object,” said Hamilton. “By combining this with velocity and size measurements from the first two layers, we hope to calculate the density of the object.”

The acoustic sensors within the first two layers measure the impact time and location using a simple triangulation algorithm. Finally, combining impact timing and location data provides impact and direction measurements of the debris.

Data gathered during the SDS investigation will help researchers map the entire orbital debris population and plan future sensors beyond the space station and low-Earth orbit, where the risk of damage from orbital debris is even higher to spacecraft.

“The orbital debris environment is constantly changing and needs to be continually monitored,” said Hamilton. “While the upper atmosphere causes debris in low orbits to decay, new launches and new events in space will add to the population.”

Hey!! I find marine biology super cool, but everyone tells me I won't get a stable salary from it. Any advice?

Hello!! So sorry about the late reply. Anyway, I understand your struggle with people constantly wondering about the financial stability of a scientific career. For some scientific careers, especially those relating to marine biology, it is hard to estimate earnings because there are so many different pathways to chose from. What I mean by this is that your could take your passion for the ocean and work in many different places doing vastly different things. For example, you could work at a university teaching students and researching, or you could work in an aquarium taking care of animals, or you could work at a private research company/consulting firm. Each of these paths have different salary ranges. Another thing about marine biology is that it is a highly competitive field (and may be one of the reasons why people see this career as less stable than others.) 

I will not lie to you and say that marine biology careers are the most lucrative option out there; however, this does not mean that you cannot make a stable salary! Marine science careers, in my opinion, are more about your passion and drive to discover, educate, or conserve. So my main advice would be to continue doing what you love. If you are passionate about marine biology you will find that the advantages far outweigh the few downfalls. Also if you are not quiet sure if a career in marine sciences is your calling then you still have plenty of time to figure it out. Try interning or volunteering where you may be able to earn some experience.

Sorry about my rambling!! I hope it helped at least. 

And if it didn’t I highly suggest you check out SciAll.org’s YouTube channel. He has some cool videos. The video I linked here may help to answer your question.

Thank you so much and have a Thresher Shark for the road!!

Ribbons and pearls -the barred spiral galaxy NGC 1398 [3416 x 3463]

It’s just… Beautiful! Isn’t it?