Category: Astronomy

How far can Voyager 1 go before we lose contact?

Post author By M. Özgür Nevres
Post date January 10, 2019
8 Comments on How far can Voyager 1 go before we lose contact?

Voyager 1 in Deep Space (Artist Conception) — Voyager 1 in Deep Space (Artist's Conception). Since the Voyager spacecraft are identical, it could be Voyager 2, as well. The Voyager spacecraft were built by JPL, which continues to operate both. JPL is a division of Caltech in Pasadena. California. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate in Washington. Image: NASA.gov

Launched by NASA on September 5, 1977, to study the outer solar system, the Voyager 1 is the furthest human-made object from Earth. As of October 2022, it is more than 14,749,847,051 miles (23,737,577,852 km) away from our home planet. It is also moving away at a speed of 38,026.77 mph (61,198.15 km/h) relative to the Sun.

Despite that huge distance (even the light covers that distance in almost 22 hours!), thanks to NASA’s Deep Space Network (DSN), we can still communicate with it (also with its sister, Voyager 2). But how far can Voyager 1 go before we lose communication?

What if the Earth was tidally locked to the Sun?

Post author By M. Özgür Nevres
Post date January 7, 2019
No Comments on What if the Earth was tidally locked to the Sun?

Sunrise from space (NASA) — Image: NASA - ISS013-E-78960 (9 Sept. 2006) - A rising sun and Earth's horizon are featured in this image photographed by an Expedition 13 crew member on the International Space Station.

We only see one side of the moon, because it is tidally locked to the planet Earth (tidal locking the situation when an object’s orbital period matches its rotational period). What if the Earth was tidally locked to the Sun?

Space Exploration Astronomy Solar System

486958 Arrokoth image against a starry background

Post author By M. Özgür Nevres
Post date January 5, 2019
No Comments on 486958 Arrokoth image against a starry background

Ultima Thule (cropped image) — An Ultima Thule image in original context against a starry background (i.e., not zoomed in).

A beautiful 486958 Arrokoth image (initially nicknamed Ultima Thule) taken by the Long Range Reconnaissance Imager (LORRI) aboard NASA’s New Horizons spacecraft in original context against a starry background (i.e., not zoomed in).

Astronomy

100 Million Stars in the Andromeda Galaxy [amazing video!]

Post author By M. Özgür Nevres
Post date January 2, 2019
No Comments on 100 Million Stars in the Andromeda Galaxy [amazing video!]

Andromeda Galaxy Hubble Image hs-2015-02-a — To better understand what stars compose the Andromeda galaxy, a group of researchers studied the nearby spiral by composing the largest image ever taken with the Hubble Space Telescope. The result, called the Panchromatic Hubble Andromeda Treasury (PHAT), involved thousands of observations, hundreds of fields, spanned about a third of the galaxy, and resolved over 100 million stars. In the featured composite image, the central part of the galaxy is seen on the far left, while a blue spiral arm is prominent on the right. The brightest stars, scattered over the frame, are actually Milky Way foreground stars. The PHAT data is being analyzed to better understand where and how stars have formed in M31 in contrast to our Milky Way Galaxy, and to identify and characterize Andromeda's stellar clusters and obscuring dust. Though the Andromeda galaxy is 2.5 million light-years from Earth, it is our galactic next-door neighbor on the universal scale. The Hubble Space Telescope is powerful enough to resolve individual stars in a 61,000-light-year-long stretch of the galaxy's pancake-shaped disk. It's like photographing a beach and resolving individual grains of sand. And there are lots of stars in this sweeping view - over 100 million, with some of them in thousands of star clusters seen embedded in the disk. Image Credits: NASA, ESA, J. Dalcanton, B.F. Williams, and L.C. Johnson (University of Washington), the PHAT team, and R. Gendler. This is a resized image. You can see the HD image on the NASA website

In January 2015, NASA released the largest image ever of the Andromeda galaxy, called the Panchromatic Hubble Andromeda Treasury (PHAT), taken by the Hubble telescope. This composite image involved thousands of observations, hundreds of fields, spanned about a third of the galaxy and resolved over 100 million stars.

Totaling 1.5 billion pixels and requiring 4.3 gigabytes of disk space, this photo provides a detailed glimpse at the sheer scale of our nearest galactic neighbor.

Using this gigantic image, filmmaker Dave Achtemichuk created an unforgettable interactive experience.

Solar System Astronomy Planet Earth

The sidereal days and axial tilts of the Planets

Post author By M. Özgür Nevres
Post date December 31, 2018
No Comments on The sidereal days and axial tilts of the Planets

Solar System Planets' sidereal days and axial tilts

NASA Goddard Planetary Scientist James O’ Donoghue created a nice animation showing the sidereal days and axial tilts of the solar system planets.

Astronomy Technology

Casting a $20 Million Mirror for the World’s Largest Telescope (Giant Magellan Telescope)

Post author By M. Özgür Nevres
Post date December 20, 2018
No Comments on Casting a $20 Million Mirror for the World’s Largest Telescope (Giant Magellan Telescope)

The Giant Magellan Telescope (GMT) is a ground-based extremely large telescope under construction, planned for completion in 2025. When completed, it will be the world’s largest telescope and one member of the next class of giant ground-based telescopes that promises to revolutionize our view and understanding of the universe. It will be constructed in the Las Campanas Observatory in Chile.

GMT has a unique design that offers several advantages. It is a segmented mirror telescope that employs seven of today’s largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface 24.5 meters, or 80 feet, in diameter with a total collecting area of 368 square meters. The GMT will have a resolving power 10 times greater than the Hubble Space Telescope!

Solar System Astronomy

Farout: the most-distant body ever observed in Solar System

Post author By M. Özgür Nevres
Post date December 18, 2018
No Comments on Farout: the most-distant body ever observed in Solar System

The distance of Farout from the Sun — Solar system distances to scale showing the newly discovered 2018 VG18, nicknamed "Farout," compared to other known solar system objects. Farout is currently about 11,160 million miles (around 18 billion kilometers) from the Sun. That's around 120 AU, which is 120 times the distance between the Sun and Earth. This makes it the first Solar System object observed beyond 100 AU. Credit: Roberto Molar Candanosa and Scott S. Sheppard, Carnegie Institution for Science. Image Source: Carnegie Science

Researchers discovered the farthest known object in our solar system and named it “Farout” (far-out-there). It is about 120 times farther than Earth is from the Sun (120 AU, see notes 1). For comparison, the most distant planet, Neptune is about 30 AU from the Sun. At its most distant, once upon a time the ninth planet, now a dwarf planet, Pluto, can be 49 AU (7.29 billion km, or 4.53 billion miles) from the Sun. Currently, Pluto is at about 34 AU, making Farout more than three-and-a-half times more distant than the Solar System‘s most-famous dwarf planet.

Solar System Astronomy

Yet Another Scale Model of the Solar System [Video]

Post author By M. Özgür Nevres
Post date December 17, 2018
No Comments on Yet Another Scale Model of the Solar System [Video]

A scale view of the Sun and the planets — In his YouTube channel, The Science Asylum, physicist Nick Lucid provides yet another scale model of the solar system. A very nice video conceptualizing how mind-bogglingly big our solar system (and space) is. Image: from the video titled "The Craziest Solar System Model EVER!" on Science Asylum channel on YouTube.

Previously I posted articles titled “If The Moon Were Only 1 Pixel – A Tediously Accurate Map Of The Solar System” and “A Scale Model Of Solar System Drawn In The Desert And The Result Is Stunning”. Since the human brain cannot deal with really large numbers, these articles provide amazing ways to understand how big actually our Solar System is.

Now, in his YouTube channel, The Science Asylum, physicist Nick Lucid provides yet another scale model of the solar system. A very nice video conceptualizing how mind-bogglingly big our solar system (and space) is.

Astronomy Solar System

Size Comparison of the Sun and the Planets

Post author By M. Özgür Nevres
Post date November 19, 2018
5 Comments on Size Comparison of the Sun and the Planets

Sun, planets and dwarf planets size comparison — An illustration of the solar system to scale, created by the San Francisco-based artist Roberto Ziche. The image features the Sun in the background with the planets, Moon and the four dwarf planets lined up in the foreground in the relative scale of size to one another. The radiuses of the celestial bodies in the image: Sun: approximately 695,700 km (432,300 mi) Planets (and moon) Mercury: 2,440 km (1,516 mi) Venus: 6,052 km (3,760 mi) Earth: 6,371 km (3,959 mi) Moon: 1,737 km (1,079 mi) Mars: 3,390 km (2,106 mi) Jupiter: 69,911 km (43,441 mi) Saturn: 58,232 km (36,184 mi) Uranus: 25,362 km (15,759 mi) Neptune: 24,622 km (15,299 mi) Dwarf Planets Pluto: 1,188 km (738 mi) Haumea: 816 km (507 mi) Makemake: 750 km (466 mi) Eris: 1,186 km (737 mi) You can see the full-size image on Roberto Ziche's website. Ziche says: "At the Chabot Space and Science Center there were some old, poor quality images, probably downloaded from the internet and printed on office paper, showing the Sun and the planets to scale. I found the images content to be extremely interesting, but the design and quality was definitely something that could have been improved. I decided to give it a try, and create a brand new, more artistic view of our solar system, poster size (36″x36″), and donate it to the Center to replace those old prints. The 3D geometry was not too complex, but there was a lot of lighting experimentation to get the scene illuminated only by the Sun itself, and some time-consuming multi-layer composition in Photoshop."

This size comparison of the Sun and the planets in our solar system is going around frequently, but it’s still amazing to see it. Created by the San Francisco-based artist Roberto Ziche, the image features the Sun in the background with the planets, Moon, and the four dwarf planets lined up in the foreground in the relative scale of size to one another.

Astronomy

How Many Stars Can One See with the Naked Eye?

Post author By M. Özgür Nevres
Post date November 17, 2018
No Comments on How Many Stars Can One See with the Naked Eye?

Have you ever wondered how many stars one can see with the naked eye? On a clear, moonless night far from city lights, a healthy naked eye can perceive around 2,500 to 4,000 stars in the night sky. This number varies depending on your location and conditions, as light pollution and atmospheric clarity significantly affect visibility. While the entire Milky Way galaxy contains billions of stars, our eyes can only glimpse a fraction of them. Photo by Vincent Chin on Unsplash

When you look up at the night sky in a place without light pollution, the view is magnificent: thousands of stars and the Milky Way galaxy offer a unique visual feast. But have you ever wondered how many stars you are looking at at that moment? How many stars can you see in the sky with the naked eye?