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Dubai Astronomy Group

A Journey Through
The Cosmos

From our fragile blue home to the faintest echo of creation — scroll to travel the full scale of the universe, one step at a time.

Scroll to begin
01 — Starting Point

Earth

The Pale Blue Dot

Our home. Seen from space, it is a fragile sphere of blue and white — the only world in the known universe confirmed to harbour life. Over 4.5 billion years, Earth evolved from a molten rock into an ocean-draped world wrapped in a life-sustaining atmosphere. That thin shell of air, stretching barely 100 km above us, is the only thing standing between us and the vacuum of space.

Diameter12,742 km
Distance from Sun149.6 million km
Surface covered by ocean71%
Age4.54 billion years
02 — 384,400 km from Earth

The Moon

Earth's Faithful Companion

Earth's only natural satellite, and the only world beyond our own ever walked by human feet. The Moon was born in catastrophe — a Mars-sized body called Theia is thought to have collided with early Earth, flinging debris into orbit that coalesced into the Moon we see today. Without it, Earth's axial tilt would be far less stable, and complex life may never have emerged.

Diameter3,474 km
Distance from Earth384,400 km
Surface temperature−173°C to 127°C
Human visitors12 astronauts (1969–72)
03 — 57.9 million km from the Sun

Mercury

The Swift Planet

The smallest planet and the closest to the Sun, Mercury is a world of dramatic extremes. Its cratered surface looks much like our Moon — battered by billions of years of impacts with almost no atmosphere to protect it. Without air to retain heat, temperatures swing more than 600 degrees between day and night. Most strangely: a single day on Mercury is longer than its entire year.

Diameter4,879 km
Distance from Sun57.9 million km
Surface temperature−180°C to 430°C
Year length88 Earth days
04 — 108.2 million km from the Sun

Venus

The Veiled Planet

Often called Earth's twin because of its similar size and mass, Venus is in reality a vision of hell. Its dense atmosphere of carbon dioxide and sulphuric acid clouds has triggered a runaway greenhouse effect, making it the hottest planet in the solar system — hotter even than Mercury. Venus also rotates backwards and so slowly that the Sun rises in the west and sets in the east.

Diameter12,104 km
Distance from Sun108.2 million km
Surface temperature465°C (constant)
Day length243 Earth days
05 — 227.9 million km from the Sun

Mars

The Red Planet

Rust-coloured and hauntingly Earth-like, Mars holds the solar system's tallest volcano — Olympus Mons, three times the height of Everest — and a canyon system, Valles Marineris, as wide as the continental United States. Evidence of ancient rivers and lakes suggests Mars was once warm and wet. Today, robotic rovers search its rust-red dust for signs that life once took hold there.

Diameter6,779 km
Distance from Sun227.9 million km
Moons2 (Phobos & Deimos)
Day length24 hrs 37 min
06 — 778.5 million km from the Sun

Jupiter

The Great Giant

Jupiter is not merely the largest planet — it is larger than all other planets combined, with over 1,300 Earths fitting inside it. Its Great Red Spot, a storm wider than Earth itself, has raged for at least 350 years. Jupiter's immense gravity acts as a cosmic shield, deflecting or absorbing many asteroids and comets that might otherwise threaten the inner solar system — and life on Earth.

Diameter139,820 km
Distance from Sun778.5 million km
Moons95 (inc. Europa, Io)
Day length9.9 hours
07 — 1.43 billion km from the Sun

Saturn

Lord of the Rings

Nothing in the solar system prepares you for Saturn. Its rings — made of billions of ice and rock particles — span up to 282,000 km across, yet are often less than 10 metres deep. Saturn is the least dense planet in the solar system; it would float on water. Its moon Titan is the only moon with a thick atmosphere and has lakes of liquid methane pooled on its surface.

Diameter116,460 km
Distance from Sun1.43 billion km
Moons146 (inc. Titan, Enceladus)
Ring spanUp to 282,000 km wide
08 — 2.87 billion km from the Sun

Uranus

The Tilted World

Uranus rolls through space almost completely on its side, tilted at 97.8 degrees — almost certainly the result of a violent collision with an Earth-sized body billions of years ago. This extreme tilt means each pole endures 42 years of continuous sunlight followed by 42 years of total darkness. An ice giant rather than a gas giant, its interior is made of water, methane, and ammonia ices beneath a hydrogen atmosphere.

Diameter50,724 km
Distance from Sun2.87 billion km
Axial tilt97.77°
Moons27
09 — 4.5 billion km from the Sun

Neptune

The Windy Giant

The most distant major planet was discovered not through observation, but through pure mathematics. Astronomers noticed irregularities in Uranus's orbit, calculated where an unseen planet must be, and found Neptune exactly where the equations predicted. Despite receiving 900 times less sunlight than Earth, Neptune generates fierce internal heat, driving winds of up to 2,100 km/h — the fastest in the solar system.

Diameter49,244 km
Distance from Sun4.5 billion km
Wind speedsUp to 2,100 km/h
Year length165 Earth years
10 — Zooming out

The Solar System

Our Sun and its family

Step back far enough and our entire planetary family shrinks into a single view. Eight planets, 290+ moons, millions of asteroids, and countless comets all orbit a single star. But the solar system doesn't end at Neptune. The Oort Cloud — a vast, spherical shell of icy bodies — extends nearly two light-years from the Sun. Voyager 1, launched in 1977, only crossed the edge of the heliosphere in 2012.

Age4.6 billion years
Heliosphere extent~120 AU
Oort Cloud extent~100,000 AU
Known planets8 + 5 dwarf planets
11 — Our galaxy

The Milky Way

One of Two Trillion Galaxies

Pull back far enough and our entire solar system shrinks to invisibility — just one of 100 to 400 billion stars orbiting the centre of the Milky Way. Our Sun lies on the Orion Arm, a minor spiral arm about 26,000 light-years from the galactic core. At the heart of the Milky Way lurks Sagittarius A*, a supermassive black hole 4 million times the mass of our Sun.

Diameter~105,700 light-years
Stars100–400 billion
Central black holeSagittarius A* (4M☉)
Age~13.6 billion years
12 — Millions of light-years

The Local Group

Our Galactic Neighbourhood

The Milky Way is not alone. It belongs to a family of over 80 galaxies called the Local Group, spanning about 10 million light-years. The dominant neighbour is the Andromeda Galaxy (M31), 2.5 million light-years away and visible to the naked eye from a dark site. Andromeda and the Milky Way are on a slow collision course. In about 4.5 billion years they will merge — forming a new elliptical galaxy astronomers have nicknamed "Milkomeda."

Members~80 galaxies
Diameter~10 million light-years
Andromeda distance2.537 million light-years
Merger in~4.5 billion years
13 — The grand scale

The Observable Universe

Everything we can ever see

Every single dot of light in this Hubble image is not a star — it is an entire galaxy, each home to hundreds of billions of stars. The observable universe — the sphere from which light has had time to reach us in 13.8 billion years — contains an estimated 2 trillion galaxies. And this is only the portion we can observe. The full universe beyond our horizon may be vastly larger. Perhaps infinite.

Diameter~93 billion light-years
Age13.8 billion years
Estimated galaxies~2 trillion
Estimated stars~10²⁴
14 — The Beginning

The Cosmic Microwave
Background

The First Light in the Universe

This is as far back as light can take us. The Cosmic Microwave Background is the faint thermal afterglow of the Big Bang — radiation that filled the universe 380,000 years after creation, when the cosmos cooled enough for atoms to form and light to travel freely for the first time. The tiny temperature fluctuations across this map — just 0.00001°C — are the seeds from which all galaxies, stars, planets, and we ultimately grew.

Temperature2.725 K (−270.4°C)
Age of signal380,000 yrs post–Big Bang
Discovered1965 — Penzias & Wilson
Mapped byCOBE, WMAP, Planck
End of Journey

"We are made of star stuff."

— Carl Sagan

Every atom in your body was forged inside a dying star. The iron in your blood came from supernovae that exploded billions of years before Earth existed. The calcium in your bones was scattered across the cosmos and eventually found its way here. You are not separate from the universe — you are the universe, looking back at itself and asking why.

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