Author: Doris W.

The European Space Agency (ESA) heads for Jupiter in 2023! The spacecraft will launch from South America and arrive at Jupiter in 2031. After orbit insertion at Jupiter, the spacecraft will spend three years observing both Jupiter and three of its largest moons.  

The mission is the first “large class” mission in the ESA’s Cosmic Vision 2015-2025 program. JUICE (JUpiter ICy moons Explorer) is the ESA’s project. The spacecraft will spend seven or eight years traveling toward Jupiter with a tentative arrival date/Jupiter orbit date of 2031.

The mission will conclude when the spacecraft intentionally crashes into one of Jupiter’s moons.

Flight Paths

The flight path from Earth to Jupiter will last approximately seven to eight years. The spacecraft will orbit Jupiter’s moons for about three and a half years collecting data. 

Flight Path to Jupiter

The JUICE mission will launch from the European Spaceport in Kourou, French Guiana. The Ariane 5, “The Heavy Launcher,” will carry the spacecraft.  

The spacecraft will take advantage of gravity assists from Earth (three different times!), Venus and Mars to increase the spacecraft velocity and reduce the flight time.

Flight Path around Jupiter’s Moons

JUICE will use the gravity from Ganymede, Callisto, and Europa to adjust its flight trajectory during flybys past each moon to stabilize and optimize its orbit. JUICE will collect data from Jupiter, Callisto, and Europa during the flybys.  

JUICE will be placed into a highly elliptical orbit around Ganymede before the mission’s conclusion. 

Timeline

In 2022, the ESA finalized the launch window for the JUICE mission. Launching the spacecraft within this time window will allow gravity assistance from the Earth and Venus.

Date	Event
April 5th-25th 2023	Launch
August 2024	Earth flyby-Gravitational Assist (1)
August 2025	Venus flyby
September 2026	Earth flyby-Gravitational Assist (2)
January 2029	Earth flyby-Gravitational Assist (3)
July 2031	Enter Jupiter Orbit
July 2032	Europa flybys
August 2032-August 2033	Callisto flybys
December 2034	Enter Ganymede orbit
+200 DAYS	Possible mission extension
September 2035	Crash spacecraft into Ganymede

Mission Objective

JUICE has different objectives for three of Jupiter’s moons, Ganymede, Callisto, and Europa.

Ganymede

1. Ocean water (sub-surface) characterization
2. Search for theoretical subsurface water reservoirs 
3. Mapping the surface of the moon
   1. Topographical
   2. Geological
   3. Compositional
4. Moons core characterization
   1. Internal mass distribution
   2. Evolution and dynamics.
5. Exosphere 
6. Magnetic fields

Callisto 

Ganymede and Callisto have the same objectives. 

Europa

1. Organic molecules
2. Formation of surface crust
3. Non-water-ice elemental composition

What are Scientists the Most Excited About?

In a word, Habitability. Planetary scientists spent decades looking for planets in our galaxy similar to Earth in relation to their atmosphere and elemental composition.  

Today scientists have shifted their telescope lens (so to speak) and are instead looking at planets and moons that might have subsurface oceans that can support life. 

The Galilean moons of Jupiter are more similar to other planets than they are to other moons. Long considered dormant, cold, icy blocks of ice, the Galilean moons have planetary scientists enthused about potentially habitable underground oceans. There are two vital primary questions planetary scientists hope to be able to answer based on the data from JUICE.

1. Does extra-terrestrial life exist? (Hint: Think single-cell organisms, not sharks and whales.)
2. How are planets formed?

It’s Getting Busy Around Jupiter’s Moons!

The European Space Agency, NASA, and China are planning large-scale missions to Jupiter and its moons in the coming years. 

• The ESA will launch the JUICE mission in 2022.
• NASA plans to send the Europa Clipper toward Jupiter’s moon Europa in 2024. The spacecraft should arrive around the same time window as the ESA’s JUICE. The Clipper will collect data to allow scientists to understand its capability of supporting life.  
• China announced they’ll send the Tianwwen 4 to Jupiter’s moon Callisto in 2030. According to the China National Space Administration, “The scientific goals are still under consideration.”

Launch Time!

The eyes of the world will be on the JUICE mission when it arrives at Jupiter’s moons. With an eight-year flight time and a three to four-year mission after arriving at Jupiter, JUICE will send data for scientists to evaluate and debate for a long time. We can’t wait! 

The Voyager spacecraft were launched in 1977. Today, 46 years later, both spacecraft continue to transmit data back to Earth. NASA hoped the spacecraft would remain functional for five years!    

The primary mission of the spacecraft was the exploration of Jupiter, Saturn, their rings, and their moons.  Once the primary missions were complete, Voyager 2’s trajectory was modified to send it past Uranus and Neptune. 

To date, Voyager 2  is the only exploration to have collected data from the ice-giants Neptune and Uranus. Today both Voyagers are traveling toward far-flung constellations. 

Mission Milestones

Two Voyager spacecraft were launched in 1977.  The first spacecraft launched was named Voyager 2. The second spacecraft launched was Voyager 1.  Voyager 1 was given the “1” after its name because it would reach Jupiter and Saturn before Voyager 2.  

Event	Voyager 1	Voyager 2
Spacecraft Launch	Sept. 5, 1977	Aug. 20, 1977
Jupiter flyby	Mar. 5, 1979	Jul. 9, 1979
Saturn flyby	Nov. 12, 1980	August 26, 1981
Uranus flyby		Jan. 24, 1986
Neptune flyby		Aug. 25, 1989
Interstellar Space Entered	Aug. 1, 2012	Dec. 10, 2018
Fired trajectory correction thrusters		July 8, 2019

Where are they today?

Today both Voyagers are a long, long distance away from Earth.  Even though Voyager 2 launched before Voyager 1, Voyager 1 is traveling faster.  

	Voyager 1	Voyager 2
Approximate distance from Earth (Miles)	14.8 billion	12.2 billion
Speed (mph)	38,026	34,390
Communication Lag (hh:mm:ss)	22:05:28	18:25:45

Fun fact: Each year, between late February and early June the Earth is moving towards the Voyagers faster than the Voyagers are traveling away from Earth.  The distance from Earth to the Voyagers decreases!  As the Earth travels (in orbit around the Sun) further away from the Voyagers, the distance increases.  When space agencies discussion planetary exploration “launch windows”, this is what they’re discussing.

Why is Voyager 1 further away from Earth than Voyager 2?

The speed of Voyager 2 decreased after its flyby with Nepture and its moon Triton.  

• The optimal trajectory would maximize the effect of a planetary slingshot and increase the spacecraft’s speed.  
• A second trajectory was utilized to maximize Voyager 2’s ability to collect data from a closer flyby of Triton.  (Does it matter if Voyager 2 reaches a “destination” in 42,000 years versus 40,000 years?)  

Where are they going?

Now that they’ve completed their missions within our solar system, where are the Voyagers going?

Voyager 1

Headed toward the constellation Ophiuchus.  The estimated arrival date is the year 38,249 AD.  Voyager 1 will pass 1.7 light years from Gliese 445.  NASA didn’t have a specific plan on where to send Voyager 1 after it completed its Saturn and Titan flybys.  Gliese 445 was more or less straight ahead, so that’s the direction Voyager 1 is heading.

Voyager 2

Headed toward the constellations of Pavo and Sagitarrius.  The estimated arrival date is in the year 42,023 AD.  Voyager will pass roughly 1.7 light years away from Ross 248. 

Voyager discoveries

• Jupiter
  • Interacting hurricane-like storms
  • Erupting volcanos on Lo
  • Hints of an ocean beneath Europa
  • One new moon
• Saturn
  • Small moons in the F-Ring
  • Titan has a dense nitrogen atmosphere 
  • Methane clouds and rain
• Uranus
  • Ten new moons
  • Five new rings
  • Two new rings
  • An ocean of boiling water roughly 500  miles below the cloud tops
• Neptune
  • Five new moons
  • Four new rings
  • Great dark spot
  • 1,000 Mile Per Hour winds
  • Trition has erupting geysers
• Interstellar
  • The heliosphere, the location where interstellar space starts and the suns solar winds stop, isn’t the shape that astronomers expected to be.  
  • Cosmic rays are 3X stronger outside the heliosphere than inside it
  • Small amounts of gas detected in interstellar space.

Wrap up

The Voyagers will soon fall silent and cease broadcasting data as their power supplies are expended.  Yet, Voyager’s mission to address the fundamental questions of science remains unanswered.  What is the universe made of? Where did life begin? Are we alone in the universe?  

Perhaps 40,000 years from now, one of the Voyager spacecraft will invoke questions about Earth from a civilization far away from Earth’s shores. 

The largest celestial bodies ranging from the planets to the stars, solar systems, galaxies, galactic clusters, and superclusters.

As an illustration, available data suggests that the Earth (measuring over 40, 000km across) is only about 0.12 pixels as seen from space! Indeed the cosmos is so vast that only by numbers can we attempt to comprehend its magnificence.

The Largest Planet in the Universe

Earth is our home planet and by now and through scientific knowledge, we know that life does not revolve around earth alone. Earth has a diameter of roughly 12, 756 km. It is one of the eight planets in our Solar System.

Speaking of which, the largest planet in our Solar System is Jupiter with a radius of 69,911km (or diameter of 139, 822 km). However, the largest known planet in the Universe is an exoplanet (planet outside our Solar System) called ROXs 42Bb. It is roughly 2.5x the size of Jupiter.

The Largest Star in the Universe 

The Sun is one of the most recognizable and familiar stars that can be seen from earth. It appears bigger only because it is closer. It is by no means the biggest star, not even in our local Solar System, even though it can contain 1 million Earths.

The biggest star in the Universe would be either the Stephenson 2-18 or the UY-Scuti. The former is being contested leaving the UY-Scuti as the next best option. To put it in perspective, it has a radius 1,700 times larger than that of the Sun or a volume large enough to swallow 5 billion Suns.

The Largest Solar System in the Universe 

Our Solar System comprises the Sun (also a star) at its center, eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) orbiting around it, 146 moons, comets, asteroids and space rocks, ice, and dwarf planets such as Pluto.

Other than this, there are countless other solar systems in existence scattered across the vast cosmos. So, which is the largest solar system of them all? That would be the 2MASS J2126-840. Its orbit is said to be 140x that of Pluto’s.

The Largest Galaxy in the Universe

A galaxy typically comprises a huge collection of gas, dust, and billions of stars along with their respective solar systems, all bound together by gravity. The galaxy to which we belong is called the Milky Way. It is a spiral galaxy with more than 100 billion stars.

And no, that’s not the biggest galaxy in the universe. That title belongs to Alcyoneus. This gigantic galaxy’s diameter is 16.3 million light-years across! This means that at a speed of approximately 3 x 10⁸m/s, it’ll still take light 16.3 million years to travel across it.

The Largest Galaxy Cluster in the Universe

A galactic cluster is a group of gravitationally bound galaxies that come together to form a cluster. Now, imagine that a 6-million light-years-long galaxy like the IC 1011 combines with other gigantic galaxies to form a cluster!

It gets even bigger considering that some galaxy clusters can have hundreds and thousands of galaxies. The Local Group to which our Milky Way belongs, has a diameter of 1, 000, 000, 000, 000, 000, 000 km. But the largest known galaxy cluster is El Gordio.

The Largest Galaxy Supercluster in the Universe

And just when you thought you’ve seen it all, it gets much bigger as the Universe shows off its Superclusters. As the name suggests, these are clusters of galaxy clusters. These clusters of galactic clusters are simply humongous in size.

Our own supercluster is the Laniakea Supercluster, home to around 100, 000 galaxies. However, it pales in comparison to the Hercules-Corona Borealis Great Wall, the largest known single entity in the Universe. This Supercluster is 10 billion light-years across.

The Largest Object in the Universe

As far as the Universe is concerned, the only single entity bigger than the Hercules-Corona Borealis Great Wall supercluster is the Universe itself! As tremendous as this galactic supercluster is, it still doesn’t come close to the known Universe.

The known Universe is believed to be 13.7 billion years old and is said to span across more than 93 billion light years of space. This does not account for the yet unknown universe, nor the probable multiverse. The Universe is simply put, mind-boggling.

To say that these numbers are out of this world would be putting it mildly. The universe is extremely vast and there are no words to quantify it, only numbers will do.

Galaxies are important building blocks of the Universe as we know it. Whether you know little or nada about galaxies, we’re here to help. This post will highlight 10 fun facts about galaxies that you probably didn’t know.

The Universe is home to numerous celestial bodies that are strategically distributed throughout space. Including planets, planetary systems, suns, moons, solar systems, and of course, galaxies, among others.

Fun Fact #1: Galaxies are Almost as Old as the Universe

If you’ve ever wondered how old galaxies are, here’s the answer. Galaxies are believed to be anywhere around 13.5 billion years. They are believed to have started forming a few hundred million years after the Big Bang which occurred 13.7 billion years ago.

Fun Fact #2: Galaxies Used to Be Known as Island Universes

Philosopher, Immanuel Kant theorized that other galaxies (known as island universes) existed outside the Milky Way. Astronomers like Harlow Shapley argued otherwise. However, in the 1920s, Edwin Hubble was able to establish their existence, calling them “extragalactic nebulae.” 

Fun Fact 3#: Galaxies Comprise of Dust, Gas, and Matter

Galaxies typically consist of gas, interplanetary dust, stars, and their solar systems (including their moons, dwarf planets, asteroids, meteoroids, Kuiper belt objects, and comets, etc). All of these are gravitationally bound together.

Fun Fact #4: There are 4 Major Types of Galaxies

Galaxies come in different forms, shapes, and sizes. This has given rise to a system of classification for easy reference. The first type of galaxy is the spiral galaxy. Others include elliptical galaxies, peculiar galaxies, and irregular galaxies. 

Fun Fact #5: Our Galaxy Goes By Different Names

Our galaxy, a.k.a the Galaxy, is generally known as the Milky Way. However, that’s not its only nomenclature. It is also known as the “Silver River” in China. In the Kalahari Desert in southern Africa, it is referred to as the “Backbone of Night.”  

Fun Fact #6: Why Our Galaxy is Called the Milky Way

Our star, the Sun, is one of the billions of stars swirling in the Milky Way. It is described this way due to its appearance when viewed from earth. There’s also a Greek myth about the goddess, Hera, spraying milk across the sky.

Fun Fact #7: Galaxies are Gigantic 

Humongous doesn’t even begin to describe how monumental galaxies can be. For instance, the largest known galaxy, Alcyoneus, has a diameter of 16.3 million light-years, that’s nearly 3x the nearest contender, the IC 1011 with a diameter of 6 million light-years. 

Fun Fact #8: Galaxies are Numerous

From assuming that the Milky Way was the only galaxy, we now know that there are in fact, billions of galaxies out there. Each of these galaxies also contains numerous stars. For instance, the largest galaxy contains 100 trillion stars.  

Fun Fact #9: You Can See Some Galaxies With the Naked Eyes

Yes, you can view up to two galaxies with unaided eyes. These are our own Milky Way and the Andromeda galaxy. Although you won’t be able to view it in full, you can still see parts of them in a clear night sky.

Fun Fact #10: This is the Loneliest Galaxy in the Universe

Galaxies typically exist in groups or clusters. Each cluster can accommodate 100 to 1, 000 galaxies. These are also much larger superclusters, as well as superclusters of superclusters. But the NGC 503 is an exception. It holds the title of the world’s loneliest galaxy!

Now That You Know

Now that you know more fun facts about galaxies, we invite you to explore more about galaxies vs the universe. This will help to broaden your knowledge about how galaxies and the universe relate and function.

The next generation of planetary exploration kicks off in 2027 when NASA launches the Dragonfly Mission to Titan. Saturn’s moon Titan is the second-largest moon in the solar system.  Clouds, rain (methane), a nitrogen-based atmosphere, and weather patterns similar to Earth have scientists buzzing with excitement. 

Huygen’s Mission-2004

The Huygen probe landed on Titan in 2005 and broadcast data for 72 minutes.  Huygen captured atmospheric data as it descended through the haze and clouds.  Following the touchdown, Huygen captured and transmitted 100 pictures before the batteries ran out of power.  

The pictures and atmospheric data justified a return trip to Titan.  

The Four Phases of the Dragonfly Mission

1. Launch: Leaving Florida in 2027. The launch vehicle hasn’t been announced yet.
2. Cruise:
   • Starts when Dragonfly separates from the launch vehicle.  
   • Ends prior to Dragonfly entering Titan’s atmosphere
3. Entry, descent, landing (EDL).
   • Starts when Dragonfly is 789 miles (1,270 km) above Titan
   • Ends when Dragonfly touches down in a dune near the equator
4. Titan operation/science mission

Dragonfly Structure

The spacecraft has two components.

• Cruise stage-Located at the “top” of the spacecraft.  The cruise stage component separates from the Entry Vehicle at a specified height during atmospheric entry.  The cruise stage components will burn up, similar to how a rocket stage burns up upon reentry through Earth’s atmosphere.
  • The Cruise stage has three components.
    1. Earth Communications
    2. Propulsion
    3. Thermal control
• Entry Vehicle-three components
  • Backshell-Top component
    1. Parachute 
    2. Low gain antenna
    3. Separation systems
  • Rotorcraft lander-Middle component, protected by the Backshell above it and the heatshield below it.  
  • Heatshield-Protects the Rotorcraft lander during atmospheric entry.

Dragonfly in the Air

The Dragonfly weighs approximately 926 pounds (420 kg).  Instead of resting on wheels like previous NASA rovers, Dragonfly will rest on skids, just like a helicopter.  Lift is created via eight 53-inch (1.34 m) counter-rotating rotors.  

Landing

When the EDL is 0.75 miles (1.2 km) above Titan’s surface, the rotorcraft unit will detach from the Backshell and land itself.  Titan’s atmosphere is four times heavier than Earth’s.  Titan’s gravity is one-seventh of Earth’s gravity.  Combined, they create a perfect environment for low-power drone flights.

Surface Mobility 

The “relocatable lander” will fly to different locations during its 37-month ground mission.  The Dragonfly can fly for 30 minutes before recharging is required for the rotor motors.  The Dragonfly travels at a maximal speed of 22mph (33 kph).  Mar rover speeds max out a .1 mph (4,828 meters per hour).  

Data Analysis

Dragonfly has a plethora of hardware to analyze its surroundings.

• Mass Spectrometer: Elemental analysis
• Drills for Regolith samples from the surface and near the surface for analysis
• Gamma-Ray Neutron Spectrometer-Analysis of surface composition near the skids.
• Seismometer-Detect and measure ground movement
• Two LiDAR navigation sensors-realtime navigation sensors
• Ten Cameras to capture images! Close-up, panoramics, mosaic. 
• Optical navigation based on Cassini’s maps created from 127 flybys

Wrap Up

The Dragonfly will explore the chemistry of geographically different environments on the surface of Titan.  The elements, compounds, atmosphere, ocean, and seismic analysis are a window into Earth 3.5 billion years ago.  

Our fingers are crossed that Dragonfly will provide answers concerning whether Titan was once home to life.

The Alpha Centauri System

The Alpha Centauri system is a very typical star system. It is the closest system to the Earth and gets a lot of attention from us since it is relatively easy to observe. Like most star systems, its birthing process produced more than one star; it has three.

Alpha Centauri A and B are Sun-like yellow dwarf stars and form a binary star system. They rotate around a common point and are approximately as close to each other as Saturn and the Sun. The third star, Alpha Centauri C (also called Proxima Centauri) is a Class M red dwarf. It is not clear if Proxima Centauri is rotating around the two Alpha Centauri stars or just happens to be near them.

Is There Life in the Alpha Centauri System?

The most exciting about Proxima Centauri is that it has confirmed planets, one of which is an Earth-like planet within what is called the “habitable zone”, namely it may be the right temperature to support life as we know it. Unfortunately, Proxima Centauri is prone to emitting massive flares of energy at random intervals, which may render the planet unlivable.

What would it be like to live in a three-star solar system?

Alpha Centauri A and B may also have planets (the astronomers are not yet sure about this). If you lived on a planet orbiting Alpha Centauri A, it would appear similar to the Sun viewed from Earth, rising and setting on a regular daily schedule.

Alpha Centauri B would periodically appear in the sky, like the Moon, but much brighter. The two stars have an eccentric orbit that takes around 80 years to complete. At their closest approach, the secondary lighting from Alpha Centauri B on your planet would be as bright as typical indoor lighting. At their furthest approach, the light would be more like a dim porch light. Proxima Centauri, being a dim red dwarf, would just look like any other star in the sky.

Can we visit Alpha Centauri?

NASA is planning to send an unmanned spacecraft to the Alpha Centauri system in 2069, but it would probably take around 44 years before it arrived and another 4 years for its information to start arriving back at Earth, namely in the year 2117.

The Breakthrough Starshot program could, in theory, travel to the Alpha Centauri system in around 20 years. The Starshot program, which was co-founded by Stephen Hawking in 2016, is trying to create light sail spacecraft that can move at around 20% of the speed of light.