Magazine Posts

NASA Astronomy Picture of the Day:

Recorded during 2024, this year-spanning series of images reveals a pattern in the seasonal drift of the Sun's daily motion through planet Earth's sky. Known to some as an analemma, the figure-eight curve was captured in exposures taken only at 1pm local time on clear days from Kayseri, Turkiye. Of course the Sun's position on the 2024 solstice dates was at the top and bottom of the curve. They correspond to the astronomical beginning of summer and winter in the north. The points along the curve half-way between the solstices, but not the figure-eight curve crossing point, mark the 2024 equinoxes and the start of spring and fall. Regional peaks and dormant volcano Mount Erciyes lie along the southern horizon in the 2024 timelapse skyscape.

Photo by Betul Turksoy

The Fairmont Le Château Frontenac, formerly and commonly referred to as the Château Frontenac, is a historic hotel located in Quebec City, Quebec, Canada.

Wilfredo Rafael Rodriguez Hernandez, CC0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

The closest star system to the Sun is the Alpha Centauri system. Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star. The bright stars Alpha Centauri A and B form a close binary as they are separated by only 23 times the Earth- Sun distance - slightly greater than the distance between Uranus and the Sun. The Alphasystem is not visible in much of the northern hemisphere. Alpha Centauri A, also known as Rigil Kentaurus, is the brightest star in the constellation of Centaurus and is the fourth brightest star in the night sky. Sirius is the brightest even though it is more than twice as far away. By an exciting coincidence, Alpha Centauri A is the same type of star as our Sun, and Proxima Centauri is now known to have a potentially habitable exoplanet.

Photo by Telescope Live, Heaven's Mirror Observatory; Processing: Chris Cantrell

Jeeps riding near Natal Dunes State Park in Genipabu, Rio Grande do Norte, Brazil.

Jjunoo, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

What do you think this is? Here’s a clue: it's bigger than a bread box. Much bigger. The answer is that pictured NGC 4753 is a twisted disk galaxy, where unusual dark dust filaments provide clues about its history. No one is sure what happened, but a leading model holds that a relatively normal disk galaxy gravitationally ripped apart a dusty satellite galaxy while its precession distorted the plane of the accreted debris as it rotated. The cosmic collision is hypothesized to have started about a billion years ago. NGC 4753 is seen from the side, and possibly would look like a normal spiral galaxy from the top. The bright orange halo is composed of many older stars that might trace dark matter. The featured Hubble image was recently reprocessed to highlight ultraviolet and red-light emissions. APOD Year in Review: NASA Night Sky Network Presentation for 2024

Humoristic cartoon from Puck on the establishment of diplomatic relations between Greece and Persia. In 499 BC, the Persian Achaemenid Empire tried unsuccessfully to conquer various ancient Greek city-states. Finally in 449 BC a de facto peace was concluded and the Greco-Persian Wars effectively ended, but the two sides refused to have any relations. In 1902, Mozaffar ad-Din Shah of Persia and George I of Greece agreed to de jure recognition and after 2393 years established diplomatic relations.

Samuel D. Ehrhart, Public domain, via Wikimedia Commons. View source.

                      "The cycle of seasons, the tidals of man,
                       Revolve in the orb of the infinite plan;
                       We move to the rhythm of ages long done,
                       And each has his hour — to dwell in the sun!"

This is the last stanza of the poem "Hope" by Georgia Douglas Johnson, published in 1917. Read the full poem 

NASA Astronomy Picture of the Day:

Is this what will become of our Sun? Quite possibly. The first hint of our Sun's future was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier's list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, one of the brightest planetary nebulas on the sky and visible with binoculars toward the constellation of the Fox (Vulpecula). It takes light about 1000 years to reach us from M27, featured here in colors emitted by sulfur (red), hydrogen (green) and oxygen (blue). We now know that in about 6 billion years, our Sun will shed its outer gases into a planetary nebula like M27, while its remaining center will become an X-ray hot white dwarf star. Understanding the physics and significance of M27 was well beyond 18th century science, though. Even today, many things remain mysterious about planetary nebulas, including how their intricate shapes are created. APOD Year in Review: Night Sky Network Presentation for 2024

Photo by Christopher Stobie

Wedge-tailed grass finch (Emberizoides herbicola) in Terenos, Mato Grosso do Sul, Brazil.

Jairmoreirafotografia, CC BY-SA 4.0, via Wikimedia Commons. View source.