Moon Pairings, Planetary Highlights, and the Afterglow of Creation
This week, the Moon and planets are putting on a show; we’ll learn about some late spring constellations; and we bask in the afterglow of the Big Bang.
Greetings stargazers and night sky enthusiasts! Welcome to the night sky dispatch for the week of June 9-15, 2024. This week the Moon and planets are putting on a show; we’ll continue learning about the late spring constellations and their lore; and we turn our eyes and – strangely enough – our ears to the earliest moments of creation with a discussion on the afterglow of the Big Bang.
We kick off the week with a waxing crescent moon, which will be transitioning towards the first quarter by the end of the week. On Tuesday, June 11, you can find the moon near Regulus, the brightest star in the constellation Leo, making for a beautiful pairing in the western evening sky.
By Friday, June 14, the moon will reach its first quarter phase, which is an excellent time for viewing lunar features due to the high contrast of shadows across its surface.
On this date, look for the moon posing with Spica, Virgo’s brightest star. Spica, a hot blue giant, will be a lovely companion to the first quarter moon. This pairing will be visible in the southeastern sky as evening falls
The morning sky continues to be a treasure trove for planet watchers. Mars and Saturn will be visible in the predawn eastern sky throughout the month. Mars will shine bright in the east, with Saturn positioned higher above it. As the week progresses, you’ll notice Jupiter starting to rise higher from its initial low position on the eastern horizon.
This week we're focusing on three fascinating constellations you can spot in the early June sky: Scorpius, Sagittarius, and Aquila.
First up, we have Scorpius the Scorpion. This striking constellation is prominent in the southern sky during summer nights. Look for it rising in the southeast after sunset. Scorpius is home to the brilliant red supergiant star Antares, often called the "Heart of the Scorpion". According to Greek mythology, Scorpius is the scorpion sent by Gaia to kill the hunter Orion. As a tribute, they were placed on opposite sides of the sky, forever chasing each other but never meeting.
Moving eastward, we find Sagittarius the Archer. Best visible in the summer months, Sagittarius rises in the southeast and is known for the distinctive Teapot asterism. This asterism resembles a teapot with the Milky Way flowing out of its spout like steam. Within Sagittarius, you can find stunning deep-sky objects like the Lagoon Nebula (M8) and the Trifid Nebula (M20), both visible with binoculars or a small telescope. Sagittarius represents a centaur archer in mythology, often associated with Chiron, known for his wisdom and teaching ability.
Last but not least, we have Aquila the Eagle. This constellation soars high in the summer night sky and is located along the Milky Way. Its brightest star, Altair, is part of the Summer Triangle, a prominent asterism that includes Vega in Lyra and Deneb in Cygnus. In mythology, Aquila is the eagle that carried Zeus’s thunderbolts. The constellation is also linked to the story of Ganymede, the young boy taken by Zeus in the form of an eagle to become the cupbearer to the gods.
Some old favorites are still prominent in the sky. In the northwest, the Big Dipper, part of Ursa Major, is prominent. Use its two pointer stars on the edge of the dipper to find Polaris, the North Star. Following the arc of the Big Dipper's handle will lead you to the bright orange star Arcturus in Boötes and further to Spica in Virgo.
Another constellation worthy of observation is Hercules. Located between Vega in Lyra and Arcturus in Boötes, Hercules is home to M13, the Great Hercules Cluster, a spectacular globular cluster visible with binoculars.
For those with telescopes, don’t miss the chance to observe the Ring Nebula (M57) in Lyra, near Vega. This planetary nebula is a favorite for its distinct ring shape. Also, look for the Dumbbell Nebula (M27) in Vulpecula, a bit more challenging but rewarding for its hourglass shape.
That’s it for our night sky tour this week but let’s dive into something truly cosmic—something that takes us back to the very beginning of the universe itself. The discovery of the cosmic microwave background.
The Afterglow of the Big Bang
The story of the Cosmic Microwave Background, or CMB, is a journey through time and space, full of groundbreaking discoveries and brilliant minds. So, let's start at the beginning—about 13.8 billion years ago at the birth of the universe.
The Big Bang is the generally accepted theory of the origin and expansion of the universe. The Cosmic Microwave Background is essentially the Big Bang’s afterglow.
When the universe was born, it was incredibly hot and dense, a soup of particles and radiation. As it expanded, it cooled down, allowing protons and electrons to combine and form neutral atoms. This process, known as recombination, occurred around 380,000 years after the Big Bang. Before recombination, the universe was believed to be opaque because free electrons scattered photons in all directions. Once neutral atoms formed, photons could travel freely, and the universe became transparent. The CMB is made up of these ancient photons, now stretched high into the microwave region of the electromagnetic spectrum thanks to the expansion of the universe.
The existence of the CMB was first predicted by scientists Ralph Alpher and Robert Herman in the late 1940s, based on the Big Bang theory proposed by Georges Lemaître. However, it wasn't until 1965 that the CMB was accidentally discovered by Arno Penzias and Robert Wilson, two radio astronomers working at Bell Labs in New Jersey. They were trying to eliminate noise from their microwave antenna but found a persistent hiss that came from every direction. This noise turned out to be the Cosmic Microwave Background radiation, confirming a key prediction of the Big Bang theory. Penzias and Wilson received the Nobel Prize in Physics for this discovery in 1978.
Since then, the study of the CMB has evolved with advancements in technology and space missions. One of the most significant missions was the COBE satellite, launched by NASA in 1989. COBE, short for Cosmic Background Explorer, provided the first detailed measurements of the CMB, revealing tiny temperature fluctuations, or anisotropies, that correspond to the seeds of galaxies and large-scale structures we see today. COBE's findings earned John Mather and George Smoot the Nobel Prize in Physics in 2006.
Building on COBE's success, the Wilkinson Microwave Anisotropy Probe (WMAP), launched in 2001, provided even more detailed data. WMAP's measurements helped refine the age of the universe to 13.8 billion years and improved our understanding of its composition, showing that the universe is about 5% ordinary matter, 27% dark matter, and 68% dark energy.
In 2009, the European Space Agency launched the Planck satellite, which further enhanced our understanding of the CMB with unprecedented precision. Planck's data has given us the most detailed map of the CMB to date, confirming and refining the cosmological parameters obtained by WMAP.
So, what has the CMB revealed about our universe? For starters, it's a snapshot of the infant universe, providing a wealth of information about its early conditions. The tiny temperature fluctuations we observe in the CMB tell us about the density variations that eventually led to the formation of galaxies and clusters. It also gives us clues about the universe's geometry, indicating that it is flat with only a 0.4% margin of error. Additionally, the CMB has provided insights into the mysterious dark matter and dark energy that make up the majority of our universe's mass-energy content.
Recently, researchers have continued to study the CMB to test new theories and models of the universe. For example, the search for B-mode polarization in the CMB, which would be evidence of gravitational waves from the inflationary period of the universe, is ongoing. These gravitational waves are ripples in space-time that could provide direct evidence of inflation, a rapid expansion of the universe that occurred fractions of a second after the Big Bang.
In 2022, a study using data from the Atacama Cosmology Telescope and the South Pole Telescope provided new measurements of the CMB. These high-precision measurements have allowed scientists to refine our cosmological models and test the predictions of the standard model of cosmology.
One of the key findings involved more accurate determinations of the Hubble constant, which describes the rate of the universe's expansion. Interestingly, the measurements from the CMB have shown a slight discrepancy when compared to those obtained from observations of distant supernovae and other local universe data. This difference, often referred to as the "Hubble tension," suggests that there might be new physics beyond our current understanding of the cosmos.
Moreover, the data from the ACT and SPT have provided insights into the nature of dark energy and dark matter. The enhanced sensitivity and resolution of these telescopes have allowed scientists to observe the subtle effects of gravitational lensing on the CMB, where massive structures in the universe distort the CMB light. These observations help map the distribution of dark matter and improve our understanding of its properties. Additionally, by studying the polarization patterns in the CMB, researchers have been investigating the potential existence of primordial gravitational waves, which would provide direct evidence for the Big Bang’s inflationary period.
The Cosmic Microwave Background is like a time machine, allowing us to peer back to the very beginning of time. It has revolutionized our understanding of the universe's origins, its composition, and its ultimate fate. As technology advances and new missions are launched, we can expect even more exciting discoveries in the years to come.
I hope you've enjoyed this journey into the depths of the cosmos as much as I have. Until next time, keep looking up, and don't forget to marvel at the stars above.
Clear skies, everyone!