Category Archives: Astronomy

On the Outskirts of our Solar System

NPR Science: Voyager 2 Bids Adieu To The Heliosphere, Entering Interstellar Space.

“Just a few months after celebrating its 41st birthday, the Voyager 2 probe has left its familiar environs and entered interstellar space — only the second human-made object in history to do so, after Voyager 1 did it in 2012.
The moment they were waiting for arrived early last month, when Voyager 2 left what’s known as the heliosphere — the vast bubble of plasma and particles generated by the sun and stirred in solar winds. This bubble ends at a boundary called the heliopause, where the sun’s magnetic field peters out and solar winds give way to interstellar space.
By one definition, that also means Voyager 2 — now more than 11 billion miles from the sun — has achieved another, much simpler-to-say feat: leaving the solar system.

It’s not the only definition, though. And the JPL itself marks the end of the solar system at the edge of the sun’s gravitational influence, on the outer boundaries of the Oort Cloud. By that measure, the lab explained, both Voyager probes “have not yet left the solar system, and won’t be leaving anytime soon.”

“It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud,” it said, “and possibly 30,000 years to fly beyond it.”

It’s full of stars!

Astronomy Picture of the Day: Tiny Planet Timelapse .

“You can pack a lot of sky watching into 30 seconds on this tiny planet. Of course, the full spherical image timelapse video was recorded on planet Earth, from Grande Pines Observatory outside Pinehurst, North Carolina. It was shot in early September with a single camera and circular fisheye lens, digitally combining one 24-hour period with camera and lens pointed up with one taken with camera and lens pointed down. The resulting image data is processed and projected onto a flat frame centered on the nadir, the point directly below the camera. Watch as clouds pass, shadows creep, and the sky cycles from day to night when stars swirl around the horizon. Keep watching, though. In a second sequence the projected center is the south celestial pole, planet Earth’s axis of rotation below the tiny planet horizon. Holding the stars fixed, the horizon itself rotates as the tiny planet swings around the frame, hiding half the sky through day and night.”

From the Earth to Space

Astronomy Picture of the Day: Rocket Launch as Seen from the Space Station. (YouTube, 1:37min) “Video Credit: ISAA, NASA, Expedition 57 Crew (ISS); processing: Riccardo Rossi (ISAA, AstronautiCAST); music: Inspiring Adventure Cinematic Background by Maryna.”

“Have you ever seen a rocket launch — from space? A close inspection of the featured time-lapse video will reveal a rocket rising to Earth orbit as seen from the International Space Station (ISS). The Russian Soyuz-FG rocket was launched ten days ago from the Baikonur Cosmodrome in Kazakhstan, carrying a Progress MS-10 (also 71P) module to bring needed supplies to the ISS. Highlights in the 90-second video (condensing about 15-minutes) include city lights and clouds visible on the Earth on the lower left, blue and gold bands of atmospheric airglow running diagonally across the center, and distant stars on the upper right that set behind the Earth. A lower stage can be seen falling back to Earth as the robotic supply ship fires its thrusters and begins to close on the ISS, a space laboratory that is celebrating its 20th anniversary this month.”

“It travels at a speed of around 28 800 km/h”

ESA Blog: 20 questions for 20 years: Happy Birthday International Space Station. “This week we celebrate 20 years since the first International Space Station module Zarya was launched into space on 20 November, 1998. To mark the occasion, we are answering 20 of your most frequently asked questions about Alexander Gerst’s time on board the orbital outpost. Read on to be enlightened…”

“Is there gravity in space?
In truth, astronauts are not floating, they’re ‘falling’. But because of the high speed of the Space Station’s orbit, they fall ‘around’ Earth – matching the way Earth’s surface curves. The moon stays in orbit around Earth for this same reason. Since astronauts have the same acceleration as the Space Station, they appear and feel weightless.”

Science Podcast

Motherboard: Science Solved It podcast.

“I grew up on shows like The X-Files and Unsolved Mysteries. I checked out books on UFOs and Bigfoot from the library. I was fascinated by all of the wondrous, unexplainable things in the universe. And I still am. Only now, as an adult, a science journalist, and a skeptic, I’m much more interested in the explanations behind these mysterious phenomena.

That’s why I created Science Solved It, a new weekly podcast from Motherboard. Each episode, I explore one of the world’s greatest mysteries that was solved by science. I talk to the actual, real live scientists who cracked the case, while also indulging in some of the bizarre conspiracy theories that accompany these mysteries. Throughout the season, you’ll hear about unexplained, underwater noises, floating lights, moving rocks, and even a cartoon that gave people seizures.”

I found the podcast via this MetaFilter post: Science Solved It: theories and solutions to strange occurances, which has links and summaries to all the episodes in the first two seasons. I especially liked the episodes about the underwater flies at Mono Lake and the moving rocks in Death Valley, because I’ve been to those places years ago – plus, now I want to go see albino redwood trees (which probably won’t happen, as their location is being kept secret for good reasons).

I’ve got a cold at the moment and spent the past two days on the couch binge-listening to all 14 episodes in the first two seasons. Highly recommended!