Artron energy

Artron energy had a connection with, apparently, both life force and with time travel. Those who travelled through the Time Vortex would absorb artron energy in the form of a "background radiation." Some life forms were even made of living artron energy.

Properties
"Artron energy. Residue of TARDIS engines. Known to be highly inimical to certain time-sensitive life forms."

- K9, The Wedding of Sarah Jane Smith

The Doctor claimed to Monarch, an Urbankan, that artron energy had a relationship to the functioning of his TARDIS (or vice versa), though he did not elaborate. (DW: Four to Doomsday) Artron energy altered and enhanced Human antibodies, making the immune system of the human in question better at fighting diseases. (TW: Reset)

Engin noted the Doctor must have a great reserves of artron energy to survive near-fatal attacks on his person while in the Matrix. (DW: The Deadly Assassin)

Both Martha Jones (TW: Reset) and Sarah Jane Smith, had elevated artron energy levels, so much so when the Bane known as Mrs Wormwood scanned her, she found this remarkable. (SJA: Invasion of the Bane)


 * The Bane called Mrs Wormwood believed this indicated passage through the Vortex, though it may also have happened as a result of contact with the TARDIS itself, or for both reasons. Her interest would tend to suggest that not all living beings possess artron energy, or at least that Humans do not usually possess it.

During the later days of the Doctor's first incarnation, the Time Lord Magnus encountered and attempted to exploit a living sphere of artron energy in space in the hope (in the words of the Doctor showing a projection of the incident) that it would have enabled the Time Lords "near-unlimited supply of temporal power and complete mastery over the Vortex". (DWM: Flashback)

During the Last Great Time War, the Daleks evolved so they could use artron energy as a power source. In this manner, a Dalek on the verge of death could be restored to operational status by the slightest touch from a time traveller. (DW: Dalek)

Physically artron energy resembled a sort of blue electricity when outside of containment. (SJA: The Wedding of Sarah Jane Smith)

Other occurrences

 * According to the Master, the Cheetah World had high levels of artron energy. (NA: First Frontier)
 * The planet Kirith, one of the few remaining planets in the far future, had high levels of artron energy in its atmosphere, due to the Panjistri using it to power their matter transporter. (NA: Timewyrm: Apocalypse)
 * Clyde Langer absorbed some artron energy from the outside of the TARDIS trying to enter it while it was trapped in a time loop made by the Trickster. He then used the energy to attack the Trickster, as he was time-sensitive. (SJA: The Wedding of Sarah Jane Smith)