The scale of Australia’s wildfires is almost too vast to comprehend. Thousands of homes have been destroyed, 28 people have died, and as many as a billion animals have been killed in the blazes. Fires have been burning in each of Australia’s six states, with New South Wales by far the worst hit. Now, astronauts aboard the International Space Station (ISS) have captured what the fires look like from space.

Christina Koch, engineer and NASA astronaut who recently took part in the first-ever all-female spacewalk, has tweeted a selection of images taken from the ISS with the caption “Australia. Our hearts and thoughts are with you.” In the striking but depressing photos, you can see smoke and dust rising from the wildfires.

Koch is not the only astronaut aboard the ISS to share heart-breaking images of Australia. A few days ago, Luca Parmitano, ISS commander and European Space Agency (ESA) astronaut, also tweeted some photos he’s taken. They show vast ash clouds and plumes of smoke rising from the country, highlighting the extent of the fast-spreading fires.

According to NASA, the smoke from the fires is far from contained within the continent. In fact, data from the NOAA/NASA Suomi NPP satellite shows that the smoke has circumnavigated the globe, traveling around the world before returning to Australia’s eastern side.

Instruments on the satellite have also detected high amounts of aerosols – particles like dust and soot – circulating Australia’s air. Not only does this pollution impact the health of those that breathe it in, but it can also even affect the weather.

“Aerosols compromise human health when inhaled by people with asthma or other respiratory illnesses,” writes NASA in a statement. “Aerosols also have an effect on the weather and climate by cooling or warming the earth, helping or preventing clouds from forming.”

Bushfires can literally create their own weather systems. Very hot air from particularly angry fires rises into the atmosphere, producing clouds called pyrocumulus clouds and pyrocumulonimbus clouds. The latter are much more extreme and sometimes called firestorms, which are essentially thunderstorms caused by intense heat like that from a bushfire or a volcanic eruption. These storms produce strong winds, which carry smoke and ash with them, and even lightning bolts, which can trigger new fires.

Up to now, the fires have ravaged more than 6 million hectares (15 million acres) of Australian land, destroying both people’s houses and wild habitats home to unique and helpless critters like koalas and wombats. The disaster is tangible evidence that we have well and truly entered the climate crisis, despite politicians around the world – Australia’s government included – failing to make the drastic policy changes required to curb the greenhouse gases that drive climate change.

Thankfully, heavy rains have just hit southeastern Australia, putting out a number of fires and helping firefighters get those still burning under better control. The rains are expected to continue over the next few days, but some of the most fire-ravaged areas remain dry. Last year was Australia’s hottest and driest year on record, and unless radical climate action is taken now, aggressive and destructive fires will become the norm for the nation and many other parts of the world in the years to come.